Work

Spectral magnetization ratchets with discrete-time quantum walks

Year: 2020

Type: article

Abstract: We predict and theoretically study in detail the ratchet effect for the spectral magnetization of periodic discrete-time quantum walks (DTQWs)---a repetition of a sequence of $m$ different DTQWs. These generalized DTQWs are achieved by varying the corresponding coin operator parameters periodically with discrete time. We consider periods $m=1$, 2, and 3. The dynamics of $m$-periodic DTQWs is characterized by a two-band dispersion relation ${\ensuremath{\omega}}_{\ifmmode\pm\else\textpm\fi{}}^{(m)}(k)$, where $k$ is the wave vector. We identify a generalized parity symmetry of $m$-periodic DTQWs. The symmetry can be broken for $m=2$ and 3 by proper choices of the coin operator parameters. The obtained symmetry breaking results in a ratchet effect, i.e., the appearance of a nonzero spectral magnetization ${M}_{s}(\ensuremath{\omega})$. This ratchet effect can be observed in the framework of continuous quantum measurements of a time-dependent correlation function of periodic DTQWs.

Source: Physical Review A

DOI: 10.1103/physreva.101.032119

Authors: A. Mallick, M. V. Fistul, P. Kaczynska, S. Flach

Institutions: Institute for Basic Science, National University of Science and Technology, Russian Quantum Center, University of Warsaw

Language: English

Topic: Quantum Computing Algorithms and Architecture

Subfield: Artificial Intelligence

Field: Computer Science

Domain: Physical Sciences

Open Access status: green

Funder: Ministry of Education and Science of the Russian Federation

Award: G1132318247