Chronological feed of everything captured from Mikhail Lukin.
paper / mikhaillukin / 1d ago
Quantum error correction (QEC) is critical for scalable quantum computing, but existing decoding algorithms limit the potential of quantum low-density parity-check codes. This research introduces a convolutional neural network (CNN) decoder that leverages geometric code structure. The CNN decoder achieves significantly lower logical error rates and higher throughput, suggesting reduced space-time costs for fault-tolerant quantum computation.
quantum-computingerror-correctionneural-networksfault-tolerancequantum-codesmachine-learningqec-decoders
“A convolutional neural network decoder can exploit the geometric structure of quantum error correction codes.”
paper / mikhaillukin / Mar 10
The protocol uses local projective measurements and unitary feedback to prepare unknown ground states of frustration-free gapless quantum systems in polynomial time scaling with system size. For single-particle dynamics, performance is analytically proven; many-body generalization relies on quasiparticle physics, with preparation time linear in the inverse finite-size gap (up to logs) when the dynamical critical exponent z ≥ effective quasiparticle dimension d. Transient cooling reveals universal critical properties, verified numerically on 1D/2D Heisenberg ferromagnets, Fredkin chain, and 2D RVB model. Fully digital, it outperforms adiabatic methods for high-fidelity access in near-term devices.
quantum-simulationdissipative-state-preparationgapless-systemsfrustration-freequantum-many-bodycritical-phenomenaarxiv-paper
“Protocol prepares ground states of frustration-free gapless systems in time polynomial in system size”
paper / mikhaillukin / Feb 20
Researchers demonstrate an analog-digital quantum simulator using Rydberg-hyperfine qubit mapping in neutral atom arrays, enabling programmable state preparation, non-destructive readout, atom reuse, and loss mitigation via reservoirs. They engineer ring-exchange and hopping dynamics via Floquet driving and measure single-excitation spectral functions. On a 271-site kagome lattice, closed-loop optimization realizes an out-of-equilibrium Rokhsar-Kivelson critical quantum spin liquid, evidenced by absent local order, long-range dimer coherences up to 18 sites, and field-theory-consistent correlations.
quantum-simulationrydberg-atomsquantum-criticalitymany-body-dynamicsneutral-atom-arraykagome-latticespin-liquid
“Coherent mapping between Rydberg and hyperfine qubits enables efficient analog dynamics with programmable preparation and measurement in neutral atom arrays”
paper / mikhaillukin / Jan 29
The method maps fault-tolerant Clifford circuits to subsystem codes via spacetime code formalism, enabling estimation of Pauli noise from syndrome data alone. It provides necessary and sufficient conditions for learnability of physical and logical errors, predicting logical fidelities accurately with polynomial sample complexity. This yields exponential advantages over logical-data-only methods like direct fidelity estimation, even for exponentially suppressed logical error rates, and is validated on synthetic and experimental data from Bluvstein et al.
quantum-computingfault-tolerant-quantumclifford-circuitsquantum-benchmarkingsyndrome-decodingspacetime-codeslogical-fidelity
“General fault-tolerant Clifford circuits can be mapped to subsystem codes using spacetime code formalism for syndrome-based noise estimation.”
paper / mikhaillukin / Jan 28
Phantom codes are quantum error-correcting codes that implement fault-tolerant entangling gates between all logical qubits in a code block solely through physical qubit relabeling during compilation, achieving perfect fidelity without spatial or temporal overhead. The authors enumerate 2.71×10^10 CSS codes up to n=14 qubits, identify further instances up to n=21 using SAT methods, and construct higher-distance families from quantum Reed-Muller and binarized qudit codes. Noisy simulations demonstrate 1-2 orders of magnitude lower logical infidelity than surface codes for GHZ preparation and Trotterized simulations at comparable overhead.
quantum-error-correctionphantom-codeslogical-qubitsentangling-gatesquantum-codesfault-tolerant-computingquantum-simulation
“Phantom codes realize entangling gates between all logical qubits in a code block purely through relabelling of physical qubits during compilation, with perfect fidelity and no spatial or temporal overhead.”
paper / mikhaillukin / Jan 18
Inverse quantum simulation inverts traditional forward simulation by minimizing a cost function encoding desired material properties on quantum hardware to prepare target many-body states. Hamiltonian learning then reconstructs a low-energy Hamiltonian for which this state is an approximate ground state, providing interpretable models for synthesis. Applications include enhancing d-wave correlations in the fermionic Hubbard model for high-Tc superconductors, stabilizing topological order, and optimizing photochemical and spectroscopic properties.
quantum-simulationinverse-simulationquantum-materialshamiltonian-learningsuperconductorstopological-orderquant-ph
“Inverse quantum simulation encodes target material characteristics as a cost function minimized on quantum hardware to prepare desired many-body states”
paper / mikhaillukin / Jan 9
Experiment demonstrates three quantum interaction regimes between a Rydberg polariton in an atomic ensemble and an adjacent single Rydberg atom: polariton blockade, coherent exchange, and probabilistic hopping, distinguished by transmission spectra. A transition through an exceptional point occurs between blockade and coherent exchange. These interactions enable fast, non-destructive Rydberg atom detection and show promise for nonlinear photonic networks.
rydberg-atomspolaritonsquantum-dynamicsexceptional-pointsatomic-physicsquantum-sensing
“Rydberg atoms coupled to single photons in atomic clouds form strongly interacting Rydberg polaritons”
paper / mikhaillukin / Dec 9
Researchers introduce dressed-state qubit encoding under a magnetic field perpendicular to the diamond lattice, enabling direct enhancement of native dipolar interactions in NV center ensembles. This yields a 3.2× improvement in the JT₂ coherence parameter over Floquet methods and 2.6× (8.3 dB) better AC magnetometry sensitivity. The extended coherence facilitates probing spin transport at intermediate-to-late times, offering a versatile tool for interacting spin systems.
quantum-physicsnv-centershamiltonian-engineeringfloquet-engineeringquantum-metrologyspin-ensemblesdiamond-spins
“Dressed-state encoding perpendicular to the lattice enhances native dipolar interactions in NV ensembles.”
youtube / mikhaillukin / Dec 2
Mikhail Lukin, Chief Scientist at QuEra, highlights a critical juncture for neutral atom quantum computing, with recent advancements enabling the integration of all necessary elements for large-scale, utility-grade machines. This progress, built on decades of foundational research, signifies a shift from theoretical concepts to practical implementation. The field now requires a co-design approach, integrating diverse disciplines and pushing scientific frontiers simultaneously to accelerate development.
quantum-computingneutral-atom-quantum-computingquantum-hardwarefault-tolerant-quantum-computingquantum-techqueraharvard-mit-collaboration
“Neutral atom quantum computing has reached a point where all elements required for large-scale, utility-level machines have been implemented and combined.”
paper / mikhaillukin / Nov 12
Quantum many-body systems exhibit local arrows of time that can deviate from the global Hamiltonian-induced time evolution, rendering time flow observer- or subsystem-dependent. The paper defines these local arrows and links them to spacetime quantum entropies. Numerical and analytical examples demonstrate manifestations including quantum thermalization and error correction phenomena.
quantum-physicsmany-body-systemsarrows-of-timequantum-thermalizationquantum-error-correctionspacetime-entropiesarxiv-paper
“In quantum many-body systems, local arrows of time can differ from the global time t induced by Hamiltonian evolution.”
paper / mikhaillukin / Oct 13
A programmable neutral-atom quantum simulator with up to 180 qubits explores quench dynamics in spin models, identifying stable dynamical regimes stabilized by Floquet-like prethermal steady states over long timescales via strong dynamical constraints. Sharp resonant peaks in the response arise from structured melting of prethermalization. In 2D, a sharp dynamical response shift, converging with system size and tied to Néel-order defect proliferation, signals a dynamical phase transition without equilibrium counterpart.
quantum-simulationneutral-atomsprethermal-dynamicsquench-dynamicsfloquet-phasesdynamical-phase-transitionmany-body-physics
“Quench dynamics experiments conducted on spin models using a neutral-atom quantum simulator with up to 180 qubits.”
paper / mikhaillukin / Oct 7
High-rate qLDPC codes extend to computation via batched operations that apply identical logical gates across multiple code blocks in parallel, achieving constant space-time overhead for arbitrary CSS codes in single-shot error correction, state preparation, surgeries, code switching, and addressable Clifford gates. Parallel non-Clifford gates follow with low space-time cost, enabling efficient compilation of parallel quantum algorithms like lattice Hamiltonian simulations. Near-term implementation uses self-dual Bivariate-Bicycle codes (encoding rate ~1/10) with transversal Cliffords and global T gates, outperforming surface codes and low-rate qLDPCs in simulation costs.
qldpc-codesfault-tolerant-quantumbatched-operationsquantum-error-correctionclifford-gatesquantum-simulationbicycle-codes
“Batched gadgets for arbitrary CSS qLDPC codes achieve constant space-time overhead for single-shot error correction, state preparation, code surgeries, code switching, and addressable Clifford gates”
paper / mikhaillukin / Sep 15
Researchers demonstrate loading, cooling, and imaging of 87Rb atom arrays in finite magnetic fields using electromagnetically induced transparency (EIT) cooling combined with fluorescence imaging. The technique achieves 99.6(3)% readout fidelity at 98.2(3)% survival probability and up to 68(2)% single-atom stochastic loading. A predictive model for survival probability aligns with this and other atom array experiments, cooling both axial and radial directions to support continuous neutral atom quantum processors.
neutral-atomsatom-arrayseit-coolingquantum-computingatomic-physicsquantum-sensors
“EIT cooling with fluorescence imaging achieves 99.6(3)% readout fidelity for 87Rb atom arrays in finite magnetic field”
paper / mikhaillukin / Sep 14
Modular attention-based neural decoders learn gate-induced error correlations, generalizing from random circuit training to multi-qubit algorithmic workloads with fast inference and logical error rates matching most-likely-error decoders. They incorporate loss-resolving readout for realistic noise, including qubit loss, and simplify design by targeting algorithm-specific observables without accuracy loss. Validated on surface and 2D color codes under circuit-level noise, these decoders provide interpretability via attention mechanisms and enable deep-circuit fault-tolerant quantum algorithms.
quantum-decodersneural-decodersquantum-error-correctionfault-tolerant-quantummachine-learning-quantumsurface-codesquantum-algorithms
“Neural decoders generalize from training on random circuits to unseen multi-qubit algorithmic workloads”
paper / mikhaillukin / Sep 11
Conventional optical imaging suffers from shot-noise-limited SNR due to signal integration and classical post-processing of asynchronously arriving photons. The proposed method encodes photonic amplitude into qubit registers for coherent quantum processing, bypassing these constraints. Applied to unresolved point source imaging for exoplanet detection, it achieves orders-of-magnitude performance gains using small-scale quantum processors under realistic conditions.
quantum-physicsquantum-computingoptical-imagingquantum-algorithmsexoplanet-detectionsignal-processingarxiv-paper
“Conventional imaging techniques are limited in SNR by shot noise accumulation during classical post-processing.”
paper / mikhaillukin / Sep 10
New method uses reconfigurable quantum systems with non-local connectivity, mid-circuit measurement, and classical feedforward to generate dynamical fermion-to-qubit mappings, reducing space-time overhead from O(N) to O(log N) for N fermionic modes. For structured circuits like fermionic FFT, overhead drops to O(1). Technique enables efficient simulation of SYK model, periodic materials, and free-fermion state preparation, with orders-of-magnitude gate reductions compatible with fault-tolerant devices.
quantum-simulationfermion-simulationreconfigurable-qubitsquantum-algorithmshamiltonian-simulationsachdev-ye-kitaevfault-tolerant-quantum
“Generic fermionic algorithms on qubits have O(N) space-time overhead for N fermionic modes”
paper / mikhaillukin / Aug 14
Tricycle codes extend bicycle codes to three homological dimensions, supporting constant-depth physical circuits for logical CCZ gates across three code blocks via new analytical and numerical methods for 3D homological products. They facilitate single-shot magic state preparation and error correction, yielding high circuit-noise thresholds above 0.5%. Simulations demonstrate logical error rates below 6e-10 for 50-100 qubit blocks with modest post-selection, optimized for reconfigurable neutral atom platforms.
quantum-ldpc-codesmagic-statesquantum-error-correctionbicycle-codestricycle-codesfault-tolerant-quantumquantum-computation
“Tricycle codes support constant-depth physical circuits implementing logical CCZ gates between three code blocks.”
paper / mikhaillukin / Aug 11
Theoretical and numerical analysis identifies a deconfined quantum critical point (DQCP) in triangular-lattice Rydberg atom arrays between ordered phases at 1/3 and 2/3 excitation densities, previously observed experimentally. Field theory predicts critical exponents for infinite cylinders and a critical conformal field theory with emergent U(1) symmetry, a DQCP hallmark, validated numerically. Results extend to ladder geometries, enabling experimental probes of U(1) symmetry via finite tweezer arrays.
deconfined-quantum-criticalityrydberg-atomstriangular-latticequantum-phase-transitionsconformal-field-theoryu1-symmetry
“A deconfined quantum critical point (DQCP) occurs between the 1/3 and 2/3 Rydberg excitation density ordered phases on a triangular lattice.”
paper / mikhaillukin / Jun 25
Researchers demonstrate a full universal fault-tolerant quantum architecture using reconfigurable arrays of up to 448 neutral atoms, implementing surface codes with 2.14x below-threshold error suppression via repeated QEC and ML decoding. They achieve logical entanglement via transversal gates and lattice surgery, extend to universal logic with 3D [[15,1,3]] codes and transversal teleportation for arbitrary-angle synthesis at logarithmic overhead, and enable mid-circuit qubit reuse boosting cycle rates by 100x for deep circuits with dozens of logical qubits using [[7,1,3]] and [[16,6,4]] codes while keeping constant entropy. These experiments elucidate principles like balancing quantum logic with entropy removal, physical entanglement in gates, and teleportation for universality and reset in neutral atom systems.
quantum-error-correctionfault-tolerant-quantumneutral-atomsquantum-architecturesurface-codeslogical-qubitsarxiv-paper
“Surface code QEC on 448 neutral atoms achieves 2.14(13)x below-threshold performance in a four-round characterization circuit”
paper / mikhaillukin / Jun 25
Researchers demonstrate continuous operation of a 3000-qubit neutral atom array using dual optical lattice conveyor belts to transport atom reservoirs into the science region for high-rate extraction into tweezers. The system reloads 300,000 atoms per second, enabling over 30,000 initialized qubits per second and sustaining the array for over two hours. Quantum coherence is preserved during refilling, supporting spin-polarized or superposition states for scalable quantum computing and metrology.
neutral-atomsquantum-computingcontinuous-operationlarge-scale-qubitsatom-arraysquantum-error-correctionoptical-tweezers
“System reloads 300,000 atoms into tweezers per second”
paper / mikhaillukin / Jun 23
This method enables quantum phase estimation using only local control operations, eliminating the need for global unitaries conditioned on auxiliary qubits. It measures the complex phase of the Loschmidt echo for circuit and Hamiltonian dynamics by tracking phase changes, trading reduced circuit depth for higher sampling and classical postprocessing costs. Applicable to any efficiently preparable state without reference states, it supports spectral property measurements in large many-body systems on current hardware.
quantum-phase-estimationlocal-controlquantum-simulationloschmidt-echohardware-efficientmany-body-systemsquant-ph
“Quantum phase estimation approach uses only locally controlled operations.”
paper / mikhaillukin / Jun 13
Researchers demonstrate coherent collective many-body dynamics in dense, disordered electron spin ensembles in diamond by applying time-dependent magnetic field gradients alongside global coherent control. This approach generates and probes nanometer-scale spin spirals, with Hamiltonian engineering enhancing microscopic interaction symmetry to achieve disorder-robust spin evolution. The technique overcomes dipolar coupling limitations from positional disorder, paving the way for interaction-enhanced quantum metrology and ambient-condition nanoscale imaging of materials and biology.
quantum-sensormany-body-dynamicssolid-state-spinsdiamond-nv-centersmagnetic-gradientsquantum-metrologydisorder-resilience
“Time-dependent magnetic field gradients combined with global coherent control realize collective many-body dynamics in dense electron spin ensembles in diamond”
paper / mikhaillukin / May 27
Researchers propose a hybrid light-matter approach for fault-tolerant blind quantum computation (BQC), leveraging high-fidelity local gates on server matter qubits and photon-based delegated blind rotations. This constructs loss-tolerant delegated gates, enabling efficient algorithm compilation and scalable fault-tolerant logical algorithms. The design improves error-correction thresholds, boosts blind logical circuit speed and depth, and maps to neutral atom arrays and solid-state spin defects.
blind-quantum-computingfault-tolerant-quantumquantum-error-correctionhybrid-light-matterquantum-networksscalable-quantum-computation
“Existing BQC protocols face scaling challenges due to photon losses, low efficiencies, and high overheads from fault-tolerant operations.”
paper / mikhaillukin / May 21
A low-overhead architecture for reconfigurable neutral atom arrays leverages transversal gate operations and dynamic connectivity to implement fault-tolerant building blocks like magic state factories, arithmetic units, and look-up tables. It achieves runtime speed-up scaling with code distance d by minimizing atom move times and decoding volume. Resource estimates show 2048-bit RSA factoring requires 19 million qubits and 5.6 days at 1 ms QEC cycles, yielding ~50x runtime improvement over prior estimates without added space.
neutral-atom-arraystransversal-gatesquantum-fault-toleranceresource-estimationshors-algorithmquantum-architecturesatom-arrays
“The architecture achieves runtime speed-up on the order of code distance d”
paper / mikhaillukin / May 19
Reformulates decoding of transversal quantum circuits by tracking logical operator products, reducing syndrome extraction rounds by code distance d while resembling single-qubit memory decoding. Enables minimum-weight perfect matching for fault-tolerant surface code decoding with thresholds matching single-qubit memory. Benchmarks show decoding runtime below conventional lattice surgery, extending single-qubit QEC to multi-qubit transversal algorithms.
quantum-error-correctionsurface-codetransversal-gatesfault-tolerant-decodingquantum-computingmagic-state-distillationdecoder-optimization
“Joint decoding of transversal gate algorithms reduces syndrome extraction rounds by factor of code distance d”
paper / mikhaillukin / May 1
Researchers demonstrate wideband magnetic correlation measurements using spectrally resolved NV centers in diamond, achieving spatial resolution below the optical diffraction limit and MHz noise sensitivity of 15 nT/√Hz. The technique leverages high-fidelity optical readout and long spin coherence for MHz-range probing, extending to GHz-range via correlated T1 relaxometry. Under external GHz noise, NV correlations reveal coherent and incoherent dynamics akin to superradiance, despite featureless individual relaxations, enabling study of nonlocal condensed-matter phenomena.
quantum-physicsnv-centersmagnetometrydiamond-magnetometerscovariance-measurementsub-diffraction-limitt1-relaxometry
“Two NV centers in diamond measure wideband magnetic signal correlations with spatial resolution below the optical diffraction limit.”
paper / mikhaillukin / Mar 18
Researchers demonstrate many-body signal amplification in a room-temperature 2D ensemble of NV centers in diamond using time-reversed two-axis-twisting interactions engineered via dynamical quantization axis control and Floquet methods. Optimal amplification occurs when backward evolution time equals twice the forward evolution time, contrasting conventional Loschmidt echoes. This arises from time-reversed mirror symmetry in the dynamics, enabling entanglement-enhanced quantum magnetic sensing.
quantum-sensingnv-centerssignal-amplificationtime-reversalmany-body-dynamicsfloquet-engineeringsolid-state-quantum
“Many-body signal amplification is achieved in a solid-state quantum sensor using NV centers at room temperature.”
paper / mikhaillukin / Mar 3
Proposes a non-variational, system-agnostic counterdiabatic (CD) expansion that converges exponentially in order, with finite-system resources scaling as the inverse spectral gap—argued asymptotically optimal. Extends to thermodynamic limit using finite-time adiabatic protocols, requiring only quantum speed limit time for ground state preparation without trajectory optimization. Outperforms variational CD methods on quantum Ising chain benchmarks.
counterdiabatic-drivingquantum-state-preparationadiabatic-protocolsquantum-ising-chainspectral-gapquantum-speed-limit
“The proposed CD expansion method converges exponentially quickly in the expansion order.”
paper / mikhaillukin / Feb 27
Develops a delayed-erasure decoder for general quantum error correction codes that leverages delayed loss detection to correct qubit loss errors in logical circuits, even without precise error timing. Identifies circuit-structure-dependent strategies for loss correction, including low-overhead syndrome integration for deep circuits and natural handling via gate teleportation in shallow subroutines. Simulations on small-angle synthesis show marked performance gains as loss fraction rises, advancing fault tolerance in loss-prone neutral atom systems.
qubit-losserror-correctionquantum-algorithmsfault-toleranceneutral-atomssyndrome-decodingquantum-computation
“Qubit loss errors are a dominant noise source in neutral atom quantum computers.”
paper / mikhaillukin / Feb 13
A fault-tolerant Bell-pair distillation protocol uses high-rate qLDPC codes to achieve constant overhead, matching the code rate without extra physical qubits. Circuit-level analysis confirms fault tolerance for input infidelities below ~10%, feasible with near-term hardware. Output Bell pairs remain encoded in qLDPC codes, bypassing un-encoding costs and enabling direct distributed quantum computation.
quantum-physicsbell-pair-distillationqldpc-codesfault-tolerantquantum-networksquantum-computing
“Distillation rate equals the qLDPC code rate with no additional qubit overhead”
paper / mikhaillukin / Jan 30
Researchers implement a digital quantum simulation of 2D fermionic systems on reconfigurable neutral-atom arrays using a Kitaev honeycomb fermion-to-qubit mapping with long-range entangled states prepared via measurement and feedforward. Fermionic evolution is achieved through Floquet engineering with tunable entangling gates and atom rearrangements, enabling preparation of topological states across the Kitaev model's phase diagram, including verification of the non-Abelian spin liquid via odd Chern number. The platform also probes fermion exchange statistics and simulates Fermi-Hubbard model dynamics on square lattices, advancing simulations for materials and chemistry.
quantum-simulationkitaev-modelneutral-atomsfermionic-systemstopological-phasesquantum-computing
“Digital simulation architecture realizes 2D fermionic systems using Kitaev honeycomb fermion-to-qubit mapping with long-range entangled states.”
paper / mikhaillukin / Dec 25
The derandomized shallow shadows (DSS) algorithm learns large sets of non-commuting Pauli observables using shallow circuits for basis rotations, minimizing sample complexity via optimized shallow measurement circuits. Tensor network techniques ensure polynomial classical resource scaling. Numerical benchmarks show DSS outperforms state-of-the-art methods for quantum chemistry energy estimation and many-body system verification, with performance improving as circuit depth increases.
quantum-shadowspauli-learningshallow-circuitstensor-networksquantum-measurementquantum-chemistrymany-body-systems
“DSS algorithm uses shallow circuits to rotate into measurement bases for learning non-commuting observables.”
paper / mikhaillukin / Dec 19
Researchers demonstrate magic state distillation using logical qubits encoded in d=3 and d=5 color codes on a neutral-atom quantum computer with dynamically reconfigurable architecture. The protocol processes multiple logical qubits in parallel, yielding output magic states with higher logical fidelity than inputs. This marks a critical experimental milestone toward scalable, universal fault-tolerant quantum computation.
magic-state-distillationlogical-qubitsquantum-error-correctionneutral-atom-quantum-computercolor-codesfault-tolerant-quantum-computing
“Magic state distillation was experimentally realized using logical qubits on a neutral-atom quantum computer.”
paper / mikhaillukin / Dec 4
Researchers demonstrate universal blind quantum computing (BQC) using silicon-vacancy (SiV) centers in nanophotonic diamond cavities over a two-node distributed network. They implement a complete set of single- and two-qubit blind gates via efficient optical interfaces, enabling a client to perform remote computations without revealing circuit details. This advances matter-qubit platforms toward scalable, modular BQC architectures, as published in Science.
blind-quantum-computingsolid-state-qubitsdistributed-quantum-networksilicon-vacancy-centersnanophotonic-cavitiesquantum-gate-set
“Blind quantum computing uses distributed systems where clients perform remote computations without disclosing circuit details.”
paper / mikhaillukin / Nov 11
Researchers experimentally probe thermodynamic costs and information flow in a silicon-vacancy spin qubit coupled to a diamond nanocavity using iterative measurement and feedback. They verify the second law and fluctuation theorem incorporating quantum information measures, and quantify reducible entropy via feedback causal structure. Non-Markovian feedback demonstrates thermodynamic advantages over Markovian protocols, extending quantum thermodynamics frameworks for real-time control.
quantum-thermodynamicsentropy-reductionquantum-informationquantum-feedbacksilicon-vacancy-qubitnonequilibrium-thermodynamicsquantum-measurement
“Iterative quantum measurement and feedback on a SiV qubit stabilizes its state while allowing verification of nonequilibrium quantum thermodynamics laws”
paper / mikhaillukin / Nov 7
Encoding combinatorial optimization problems into Rydberg atom arrays via Nguyen et al. scheme causes exponential minimum gap closure along adiabatic paths, even for trivial problems, due to quantum coherent localization of the ground-state wavefunction. This localization degrades success probability on QuEra Aquila hardware. Quantum-aware encoding modifications avoid this bottleneck, yielding exponential adiabatic performance gains.
quantum-adiabatic-optimizationrydberg-arraysquantum-encodingminimum-gap-scalinglocalization-phenomenaneutral-atom-quantumarxiv-paper
“Encoded trivial optimization problems in Rydberg arrays exhibit exponentially closing minimum gap with system size.”
paper / mikhaillukin / Oct 21
Researchers implemented a (2+1)D U(1) lattice gauge theory with dynamical matter on a Kagome lattice using Rydberg-blockaded neutral atoms, where long-range interactions produce tunable linear confining potentials between charges. They mapped the phase diagram by preparing ground states with defects, revealing substructure in the confined phase between fluctuating and broken string regimes. Quenching string states demonstrated string breaking dynamics with many-body resonances, advancing quantum simulation of high-energy physics phenomena.
quantum-simulationrydberg-atomslattice-gauge-theorystring-breakingconfinementquantum-physicshigh-energy-physics
“String breaking is observed in a (2+1)D lattice gauge theory using a neutral atom Rydberg quantum simulator.”
paper / mikhaillukin / Oct 14
Researchers demonstrate a Fabry-Perot fiber cavity coupled to single neutral atoms in optical tweezers, achieving 99.960% fidelity in fast, nondestructive qubit readout via strong atom-cavity coupling. They implement cavity-carving for probabilistic Bell state generation at 91% fidelity and 32% success rate, and a deterministic cavity-mediated entangling gate reaching 76% fidelity with integrated error detection. This platform enables modular quantum computing and networking by combining high-fidelity readout with error-detected remote entanglement.
quantum-physicsneutral-atomsoptical-cavityqubit-readoutentanglement-generationerror-detectionquantum-computing
“Qubit state readout fidelity reaches 99.960^{+14}_{-24}% using cavity coupling.”
paper / mikhaillukin / Sep 12
In electron-doped MoS2 homobilayers, indirect excitons with opposing dipoles hybridize unusually under negligible tunneling conditions, exhibiting behavior distinct from level crossing or anti-crossing. This is attributed to static random coupling that strengthens with electron density and weakens with temperature. The phenomenon indicates a spatially fluctuating order parameter representing interlayer electron coherence, a predicted many-body state previously unobserved outside quantum Hall regimes.
optical-signaturesinterlayer-coherenceindirect-excitonsmos2-bilayerstrongly-correlated-electronselectron-tunnelingarxiv-paper
“Indirect excitons with opposing dipoles in MoS2 homobilayers hybridize upon electron doping when electron tunneling is negligible”
paper / mikhaillukin / Aug 28
Researchers introduce a sequence of two-way entanglement distillation protocols using quantum error detecting codes with increasing rates, combined with fault tolerance techniques, to achieve constant-rate entanglement generation under noisy local operations. This addresses fidelity and rate bottlenecks in quantum interconnects for large-scale distributed quantum computing. Optimized schemes demonstrate an order-of-magnitude performance improvement over existing methods, accelerating distributed quantum algorithms while respecting memory constraints.
quantum-interconnectsentanglement-distillationdistributed-quantum-computingquantum-error-correctionfault-tolerant-quantumquantum-physics
“Constant-rate entanglement distillation is achievable using a sequence of two-way protocols based on quantum error detecting codes with increasing rates.”
paper / mikhaillukin / Aug 22
Topologically ordered quantum matter displays long-range entanglement patterns detectable via subsystem entropies, but direct measurement on large partitions is exponentially challenging. The proposed protocol uses local adiabatic Hamiltonian deformations to isolate universal topological features, requiring measurements only on small, finite subsystems after polynomial-time evolution. It applies generally across quantum simulators, demonstrated on abelian and non-abelian string-net models with neutral atom array simulations.
quantum-physicstopological-orderentanglementadiabatic-protocolstring-net-modelsquantum-simulationneutral-atoms
“Measuring subsystem entropies on large partitions becomes practically unfeasible for large systems”
paper / mikhaillukin / Aug 18
Researchers propose measurement-free local error correction (LEC) using faulty multi-qubit gates for syndrome extraction and error removal, optimized via reinforcement learning from a fixed gate set. Optimized LEC circuits extend logical qubit lifetimes in the 2D classical Ising model and 4D toric code, outperforming conventional Toom's rule-based LEC in sub-threshold gate error regimes. These circuits also reduce mid-circuit readout frequency while preserving 2D toric code memory and enable dissipative preparation of topologically ordered states.
quantum-error-correctionquantum-memoryreinforcement-learninglocal-error-correctiontoric-codequantum-computation
“Optimized LEC circuits extend memory lifetime better than Toom's rule-based LEC for 2D classical Ising model in sub-threshold gate error regime.”
paper / mikhaillukin / Aug 16
Photonic links enable fault-tolerant connectivity between locally error-corrected neutral-atom modules by leveraging surface code robustness to boundary noise. Fault tolerance requires local Rydberg gate errors below 1% and non-local Bell pair errors below 10%, achievable without distillation or overheads. Lens, single cavity, or cavity array interconnects yield 1-50 MHz Bell pair rates, translating to 25-2000 kHz error-correction cycles for direct logical qubit interfaces, supporting up to 100 kHz logical clock speeds.
neutral-atom-arraysfault-tolerant-quantumoptical-interconnectsquantum-networkingsurface-codesrydberg-gatesbell-pairs
“Fault-tolerance in neutral-atom array interconnects requires local two-qubit Rydberg gate errors below 1% and non-local Bell pair errors below 10%”
paper / mikhaillukin / Aug 5
Researchers introduce a Floquet engineering method for Rydberg-blockaded neutral atom arrays, using time-dependent detuning control and perturbations around periodic many-body trajectories to engineer effective Hamiltonians. This technique generates novel interactions like strong spin exchange in 1D chains, enabling gapless Luttinger liquid phases while respecting blockade constraints. Combining these excitations with blockade dynamically produces large-scale multipartite entanglement, with discussed experimental feasibility.
floquet-engineeringrydberg-atomsquantum-entanglementspin-exchangeluttinger-liquidquantum-simulationneutral-atom-arrays
“Floquet engineering via time-dependent Rydberg laser detuning controls novel interactions and entanglement in blockade regime”
paper / mikhaillukin / Aug 5
Researchers propose simulating dynamical lattice gauge theories using periodically driven Rydberg atom arrays on constrained PXP models. Frequency-modulated global pulses create controlled deviations from time-reversed trajectories, yielding effective Hamiltonians with non-perturbative multi-body interactions like ring exchange. Applied to 2D U(1) LGT on Kagome lattice, this engineers strong tunable six-body magnetic plaquette terms relative to matter kinetic energy, accessing new dynamical regimes.
quantum-simulationlattice-gauge-theoriesrydberg-atomsperiodic-drivingu1-gauge-theorykagome-lattice
“Rydberg blockade in neutral atom arrays naturally encodes local gauge constraints for lattice gauge theories via low-energy subspaces.”
paper / mikhaillukin / Jul 26
This work introduces fast, parallelizable logical gates for high-rate qLDPC codes using transversal CNOTs with modified ancilla codes derived from hypergraph products, achieving parallel Pauli product measurements (PPMs) on subgrids of logical qubits with reduced space-time costs. For 3D/4D homological product codes, PPMs operate in constant depth. It demonstrates O(1) space overhead for k-qubit GHZ preparation in O(1) cycles and magic state distillation/teleportation in O(√k log k) cycles, plus efficient quantum adders, compatible with reconfigurable architectures like neutral atom arrays.
quantum-error-correctionqldpc-codeshomological-product-codeslogical-gatesquantum-computationfault-tolerant-quantumneutral-atom-arrays
“Transversal logical CNOTs between data qLDPC and ancilla codes enable parallel PPMs on logical qubits.”
paper / mikhaillukin / Jul 15
Researchers achieve dynamical control of long-lived interlayer excitons in angle-aligned MoSe2/WSe2 heterostructures using fast electrical gating. Out-of-plane dipole moments allow electric fields to tune emission wavelength mid-lifetime, while patterned gates enable rapid local doping to toggle radiative decay rates via exciton-charge interactions. Spatial mapping reveals charge redistribution, probing electronic transport in twisted TMDs, enabling exciton-based optoelectronics and quantum processing.
excitonstmd-semiconductorsdynamical-controlheterostructuresoptoelectronicsquantum-opticsmesoscale-physics
“Electric fields dynamically control the emission wavelength of interlayer excitons via their out-of-plane dipole moment during lifetime.”
paper / mikhaillukin / Jul 3
A Rydberg atom array quantum simulator observes coarsening of antiferromagnetic domains after crossing a (2+1)D Ising quantum critical point, with correlation growth driven by domain boundary curvature. Dynamics accelerate near criticality, validated by deterministic domain preparation and tracking. Long-lived order parameter oscillations identify an amplitude (Higgs) mode, providing empirical insight into nonequilibrium quantum many-body processes.
quantum-simulatorrydberg-atomsquantum-phase-transitioncoarsening-dynamicsising-modelmany-body-physicshiggs-mode
“Coarsening of antiferromagnetically ordered domains occurs gradually after crossing the (2+1)D Ising quantum critical point”
paper / mikhaillukin / Jun 25
Researchers demonstrate fault-tolerant logical operations using only a constant number of syndrome extraction rounds for surface codes and similar QEC codes, bypassing the conventional O(d) rounds required due to measurement errors. This "transversal algorithmic fault tolerance" combines transversal gates with correlated decoding of partial syndromes, ensuring exponential suppression of logical error rates in code distance d. Circuit-level simulations confirm over an order-of-magnitude reduction in space-time costs for practical fault-tolerant quantum computation.
quantum-error-correctionfault-tolerancesurface-codetransversal-operationsquantum-computationqec-codesarxiv-paper
“Logical operations can be performed fault-tolerantly with only a constant number of extraction rounds for a broad class of QEC codes, including the surface code.”
paper / mikhaillukin / May 31
Adiabatic state preparation fails for large quantum systems due to exponentially vanishing energy gaps, prolonging required evolution times. A sweep-quench-sweep protocol incorporates a quench step to induce macroscopic state reconfigurations via large Hamming distance jumps, resembling quantum many-body scars. Experiments on QuEra's Aquila Rydberg atom array simulator validate this approach, showing superior performance over pure adiabatic methods for scalable many-body systems.
quantum-quenchshortcut-to-adiabaticityrydberg-atomsquantum-simulationmany-body-physicsaquila-simulatoradiabatic-algorithms
“Adiabatic protocols for ground state preparation are limited by the smallest energy gap during evolution, which vanishes exponentially with system size”