activity
20172020
collaborators

7 papers

cond-mat.quant-gas2020

PT-symmetric non-Hermitian quantum many-body system using ultracold atoms in an optical lattice with controlled dissipation

Yosuke Takasu, Tomoya Yagami, Yuto Ashida +3

We report our realization of a parity-time (PT) symmetric non-Hermitian many-body system using cold atoms with dissipation. After developing a theoretical framework on PT-symmetric…

quant-ph2020

Probing XY phase transitions in a Josephson junction array with tunable frustration

R. Cosmic, K. Kawabata, Y. Ashida +5

The seminal theoretical works of Berezinskii, Kosterlitz, and Thouless presented a new paradigm for phase transitions in condensed matter that are driven by topological excitations…

quant-ph2019

Deep Reinforcement Learning Control of Quantum Cartpoles

Zhikang T. Wang, Yuto Ashida, Masahito Ueda

We generalize a standard benchmark of reinforcement learning, the classical cartpole balancing problem, to the quantum regime by stabilizing a particle in an unstable potential thr…

cond-mat.str-el2019

Efficient variational approach to dynamics of a spatially extended bosonic Kondo model

Yuto Ashida, Tao Shi, Richard Schmidt +3

We develop an efficient variational approach to studying dynamics of a localized quantum spin coupled to a bath of mobile spinful bosons. We use parity symmetry to decouple the imp…

cond-mat.soft2019

Anomalous Topological Active Matter

Kazuki Sone, Yuto Ashida

Active systems exhibit spontaneous flows induced by self-propulsion of microscopic constituents and can reach a nonequilibrium steady state without an external drive. Constructing…

cond-mat.quant-gas2019

Quantum Rydberg Central Spin Model

Yuto Ashida, Tao Shi, Richard Schmidt +3

We consider dynamics of a Rydberg impurity in a cloud of ultracold bosonic atoms in which the Rydberg electron can undergo spin-changing collisions with surrounding atoms. This sys…