Czech-Japan Workshop on Quantum Technologies

Session

Session 2

28 May 2025, 11:00

103 (Faculty of Nuclear Sciences and Physical Engineering, Czech Technical University in Prague)

22. A Unified Framework for Symmetry-Induced Limitations in Quantum Information Processing

Hiroyasu Tajima (Kyushu university)

28/05/2025, 11:00

oral

Symmetry is a fundamental concept in physics and appears in a wide variety of contexts. Quantum information processing is no exception, with many theorems being well-known, such as the Wigner-Araki-Yanase (WAY) theorem, which imposes limitations on measurements, and the Eastin-Knill theorem, which restricts error correction codes.

In this talk, we give an inequality that captures the...

12. Quantum thermodynamics with quantum information flow: Theory and experiment

Takahiro Sagawa (The University of Tokyo)

28/05/2025, 11:20

long talk

Quantum thermodynamics is an active research area bridging quantum information and nonequilibrium statistical physics. A key to characterize universal behaviors of entropy production is the fluctuation theorem, which leads to the second law of thermodynamics in the regime far from equilibrium. The fluctuation theorem in classical systems has been thoroughly studied under various feedback...

18. Recurrence of unitary and stochastic quantum walks

Martin Štefaňák (CTU FNSPE)

28/05/2025, 11:50

oral

Recurrence means a return of the dynamical system to its initial state. Classical result of Polya [1] from 1920’s shows that a random walk on a line and a 2D grid returns to the origin with certainty, while it is transient on higher-dimensional lattices. For quantum walks, detection of recurrence requires partial measurement after each step [2], yielding a conditional quantum dynamics....