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Bruno P. Schnepper

Publications and source records attributed to Bruno P. Schnepper.

2 recordsLinked to original sources

Experimental observation and application of the genuine Quantum Mpemba Effect

Coherence is an inherently quantum property that deeply affects microscopic processes, including thermalization phenomena. A striking example is the quantum Mpemba effect (QME), in which a system can exhibit anomalous relaxation, thermalizing faster from a state initially farther from equilibrium than from one closer. Here, we experimentally investigate the genuine QME and observe how the dynamics of a spin-1/2 system interacting with a heat sink can be sped-up to equilibrium. The mechanism underlying this speed-up is uncovered through detailed analysis of the heat exchange process. Furthermore, we apply the QME in a quantum Otto refrigerator, thereby increasing its cooling power. This proof-of-concept experiment unveils new practical paths for improving quantum thermal tasks.

quant-ph

Entanglement dynamics of two modes coupled through a dissipative movable mirror in an optomechanical system

Nonclassical states are an important class of states in quantum mechanics, particularly for applications in quantum information theory. Optomechanical systems are invaluable platforms for exploring and harnessing these states. In this study, we focus on a mirror-in-the-middle optomechanical system. In the absence of losses, a separable state, composed of the product of coherent states, evolves into an entangled state. Furthermore, we demonstrate that generating a two-mode Schrödinger-cat state depends on the optomechanical coupling. Additionally, when the optical modes are uncoupled from the mechanical mode, we find no entanglement for certain nonzero optomechanical coupling intensities. We exactly solve the Gorini-Kossalokowinki-Sudarshan-Lindblad master equation, highlighting the direct influence of the reservoir on the dynamics when mechanical losses are considered. Then, we discuss vacuum one-photon superposition states to obtain exact entanglement dynamics using concurrence as a quantifier. Our results show that mechanical losses in the mirror attenuate the overall entanglement of the system.

quant-ph