AQP Seminar: Artificial open systems realized by NMR experiments

Abstract:

An open system has been an important problem in thermodynamics and statistical mechanics since Maxwell's age. It is also practically important for Quantum Information Processing since any systems, such as quantum sensors, quantum computers, and quantum channels, and so on, should be regarded as open systems. 

However, experimental studies on open systems have only recently emerged. They were done with well-isolated systems,  such as ultra cold atoms, ions in traps, optics, and cold electric circuits,  and thus the effects of environments can be well studied. We point out that some molecules solved in isotropic liquid are well isolated and thus they can also be employed for studying open systems in Nuclear Magnetic Resonance (NMR) experiments.

We present three types of NMR experiments as examples of our approach in order to study open systems.

(1) Crossover from Markovian to non-Markovian relaxations was realized by controlling environment, 

(2) Relaxation-like phenomena were observed in approximately isolated systems which consist of a pseudo-system and its pseudo-environment, and

(3) An entangled quantum sensor in noisy environment was simulated and we confirmed the usefulness of dynamical decoupling technique.

 (1) MPL B, 32 (2018) 1830002, DOI: 10.1142/S0217984918300028.

(2) New J. Phys. 21 (2019) 093008, DOI: 10.1088/1367-2630/ab3a25.

(3) JPSJ 89 (2020) 054001, DOI: 10.7566/JPSJ.89.054001.

(4) New J. Phys. 22 (2020) 103048, DOI: 10.1088/1367-2630/abbfcf.