Quantum Physics Research
Momentum-Space Entanglement Entropy as a Diagnostic for Dynamical Quantum Phase Transitions
This paper demonstrates that momentum-space entanglement entropy, when measured in the post-quench eigenbasis, serves as a time-independent and robust diagnostic for dynamical quantum phase transitions (DQPTs) in translationally invariant two-band systems. The study establishes a geometric link betw…
Zero-Photon Ghost Imaging Explained by Photon-Number Projection and Thermal Light Statistics
This paper presents a novel ghost imaging technique where images are reconstructed without any photons interacting with the object, or even without photons in either the signal or reference beams. This "zero-photon" ghost imaging relies on discarding all photons that interact with the object and exc…
Mathematical Obstructions to Dirac Path Measures
This paper revisits the long-standing problem of why a well-defined probability measure for a classical path integral representation of the Dirac equation in Minkowski space does not exist. It unifies two previously separate viewpoints: Zastawniak's observation regarding the distributional character…
Environmental Decoherence Improves Semi-Classical Quantum Approximations
This paper demonstrates that incorporating environmental decoherence into semi-classical models significantly improves their accuracy, achieving exact descriptions of original quantum dynamics within a toy model. This approach rectifies the limitations of standard mean-field semi-classical methods b…
Exact One-to-One Mapping Unites HEOM and Pseudomode Methods for Non-Markovian Quantum Dynamics
The paper establishes a precise equivalence between the Hierarchical Equations of Motion (HEOM) and pseudomode methods for open quantum systems with bath correlation functions (BCFs) as sums of N exponentials. Every such BCF corresponds to a physical model of N interacting pseudomodes damped via Lin…
Disorder-Induced Superfluidity Observed in Qutrit System
This research experimentally demonstrates disorder-induced superfluidity on a superconducting processor utilizing qutrit readout and control. The study identifies regions of non-vanishing condensate fraction through spatially-resolved two-point correlator measurements and observes a linearly-dispers…
Markov Chain Coupling Times Directly Bound Quantum Sampler Convergence
Temme and Wocjan introduce a framework for quantizing classical Markov chains by leveraging the coupling method — a standard tool for proving rapid mixing — to construct a completely positive and trace preserving (CPTP) quantum map. This map has a unique fixed point corresponding to the "qsample," t…