Quantum Physics
Collective excitations in ordered subwavelength atomic arrays can exhibit strongly suppressed radiative decay due to interference between light scattered by neighboring emitters. These so-called subradiant states make these systems a…
A quantum wave packet in a linear potential, i.e., under a constant force such as gravity, accumulates a cubic-in-time phase that is universal across Schrodinger-type platforms and naturally realized by Airy eigenstates. Because the…
We have introduced PT-symmetry to a central spin model by adding a PT-symmetric interaction with a tunable hermiticity parameter $\gamma$. Using the pseudo-Hermitian formalism, we applied a Dyson map to transform the non-Hermitian…
We explore how collective states of light and matter differ when the multi-level nature of the quantum emitters is fully taken into account. For closely spaced emitters, interferences between near-resonant transitions completely change the…
Entangled states of light lie at the heart of photonic quantum technologies, from distributed quantum communication to quantum-enhanced measurement and information processing. Their practical generation, however, remains constrained by the…
Deterministic spatial inhomogeneity has become increasingly relevant in experimentally engineered quantum many-body systems, where interaction gradients can strongly influence nonequilibrium dynamics. Motivated by this, we investigate…
The numerical simulation of non-Markovian open quantum systems based on the non-Markovian quantum state diffusion (NMQSD) equation is complicated by functional derivatives with respect to the stochastic process. A general numerical…
Quantum networks play a pivotal role in quantum information science, which not only provide a secure communication platform for remote access to quantum computers but also serve as the strategic core for achieving large-scale quantum…
When a photon and one member of an entangled photon pair are jointly projected onto a Bell-state measurement (BSM), the quantum state of the photon can be transferred to the distant partner of the pair without physically transmitting this…
Mapping quantum phase diagrams through classical simulation is notoriously resource-intensive, as even small systems far from the thermodynamic limit demand prohibitive computational effort. The variational quantum eigensolver (VQE) offers…
We propose a method to enhance Coulomb interaction between charged macroscopic mechanical oscillators by placing a conducting structure in their vicinity. We derive the effective motional dynamics of the two oscillators using macroscopic…
The coexistence of quantum information and classical signals in a single fiber is essential for future quantum networks that leverage the well-established optical fiber infrastructure. Although multiplexing technologies can separate quantum…
We develop a record-based account of internal time in quantum mechanics, where the formation of a stable record is represented as conditioning on actualized information, and along a history the accumulated record algebras are ordered by…
We show that internal loss and survival conditioning can activate anomalous generalized bunching in passive linear optical circuits. We introduce a conditional bunching probability that all photons occupy a target region of accessible…
Displacement-based simultaneous quantum-classical communications (SQCC) protocols, as originally proposed, are generally incompatible with the majority of useful quantum communication schemes, such as entanglement distribution or…
One of the defining features of pulsed dynamical decoupling is its suppression of a driven qubit's sensitivity to static detuning errors between the drive field and qubit resonance. In this paper, we show that dissipation, in the form of…
The decline of the working-age population is a major challenge for regional sustainability, particularly in ageing societies such as Japan. We present a methodological demonstration of a quadratic unconstrained binary optimization…
Solving high-dimensional parabolic partial differential equations (PDEs) is important in engineering, physics, and stochastic control. Deep BSDE methods reformulate semilinear PDEs as backward stochastic differential equations and admit a…
For a quantum Gibbs sampler whose mixing bottleneck is a weakly broken symmetry, I show that the correct initialization is determined by representation theory. I first prove a general speedup-versus-prefactor dichotomy: by exactly…
We characterize a noisy variant of a Quantum public encryption protocol recently introduced by Malavolta and Walter which demonstrated that the notion of everlasting security can be rigorously formulated for Quantum key distribution after…