activity
20242026
collaborators

6 papers

quant-ph2026

Approaching Carnot Efficiency at Finite Power in an Experimentally Feasible Quantum Heat Engine

Shogo Toma, Atsushi Noguchi, Ken Funo +1

Whether a heat engine can approach Carnot efficiency while maintaining finite power is a fundamental question in finite-time thermodynamics. For classical Markovian heat engines wi…

quant-ph2026

Measuring out-of-time-order correlators on a quantum computer based on an irreversibility-susceptibility method

Haruki Emori, Hiroyasu Tajima

The out-of-time-ordered correlator (OTOC) is a powerful tool for probing quantum information scrambling, a fundamental process by which local information spreads irreversibly throu…

quant-ph2025

Gibbs-preserving operations requiring infinite amount of quantum coherence

Hiroyasu Tajima, Ryuji Takagi

Gibbs-preserving operations have been studied as one of the standard free processes in quantum thermodynamics. Although they admit a simple mathematical structure, their operationa…

cond-mat.stat-mech2024

Speed-Accuracy Trade-Off Relations in Quantum Measurements and Computations

Satoshi Nakajima, Hiroyasu Tajima

In practical measurements, it is widely recognized that reducing the measurement time leads to decreased accuracy. However, whether an inherent speed-accuracy trade-off exists as a…

cond-mat.stat-mech2024

Symmetry induced enhancement in finite-time thermodynamic trade-off relations

Ken Funo, Hiroyasu Tajima

Symmetry imposes constraints on open quantum systems, affecting the dissipative properties in nonequilibrium processes. Superradiance is a typical example in which the decay rate o…

quant-ph2024

Improvement of Speed Limits: Quantum Effect on the Speed in Open Quantum Systems

Kotaro Sekiguchi, Satoshi Nakajima, Ken Funo +1

In the context of quantum speed limits, it has been shown that the minimum time required to cause a desired state conversion via the open quantum dynamics can be estimated using th…