paper / williamoliver / Apr 17
This research experimentally investigated the phase transitions in a disordered quantum many-body system using a 2D array of superconducting qubits. The study observed an intermediate non-ergodic regime exhibiting glass-like characteristics at finite temperatures. Key findings include the disappearance of spin diffusion and the onset of an Edwards-Anderson order parameter within this regime, providing evidence for a transition out of the ergodic phase in two-dimensional systems.
quantum-physicsdisordered-systemsnon-ergodic-phasesglassy-dynamicssuperconducting-qubitsspin-modelshilbert-space
“Disorder in quantum many-body systems can drive transitions between ergodic and non-ergodic phases.”
paper / williamoliver / Apr 8
Dark matter halo geometry significantly influences the morphology and classification of tidal structures, challenging traditional visual inspection methods. Projections of flattened haloes can cause shell-like structures to appear stream-like, leading to misclassifications. A clustering-based framework is necessary to accurately categorize these tidal debris formations, revealing the impact of halo shape on spatial dispersion and core density reduction of streams.
astrophysicsgalaxy-formationdark-matter-halostidal-structuresn-body-simulationsstellar-dynamics
“Flattened dark matter haloes can make shell-like tidal structures appear stream-like under different projections.”
paper / williamoliver / Mar 24
This study investigates the dominant limitations to energy relaxation time (T1) in fluxonium qubits. A circuit-based model for capacitive dielectric loss accurately describes the frequency dependence of T1. The research also compares two fabrication processes, indicating a potential, though not primary, improvement from a fluorine-based wet treatment.
fluxonium-qubitsquantum-computingsuperconducting-qubitsquantum-processorsenergy-relaxationdielectric-lossquantum-materials
“Fluxonium qubits exhibit long coherence times and high gate fidelities.”
paper / williamoliver / Mar 17
Correlated errors, stemming from sources like radiation-induced quasiparticles and mechanical vibrations, pose significant challenges to quantum error correction in superconducting qubits. This research introduces a methodology to differentiate between these error types based on their spatiotemporal and frequency characteristics. The study further demonstrates that superconducting qubit designs with a gap greater than the qubit energy effectively mitigate both radiation and vibration-induced errors, offering a pathway toward more robust quantum computing.
quantum-computingsuperconducting-qubitsquantum-error-correctionquasiparticle-dynamicsvibration-mitigation
“Correlated errors in superconducting qubits, arising from radiation and mechanical vibrations, hinder quantum error correction.”
paper / williamoliver / Mar 13
Radiation-induced correlated errors in superconducting qubits, driven by increased quasiparticle density, pose a significant challenge to quantum computing. This work investigates gap engineering strategies at both the Josephson junction ($\\\delta\\\Delta_{\\\ ext{JJ}}$) and the capacitor/ground-plane ($\\\delta\\\Delta_{\\\ ext{M1}}$) to enhance qubit resilience. Experimental results with alpha particles and electrons demonstrate that engineered gaps can reduce error severity and hasten recovery times, providing a pathway for mitigating radiation effects.
superconducting-qubitsquantum-error-correctionradiation-effectsquasiparticle-dynamicsquantum-hardware
“High-energy particles cause correlated errors in superconducting qubits by increasing quasiparticle density near Josephson junctions.”