Modelling non-Markovian and non-perturbative environments with unphysical modes

ORAL

Abstract

Pseudo-modes are discrete effective modes used to model the effect of continuum environments on open quantum systems. Here we develop a new approach to pseudomodes to deal with a quantum system ultra-strongly-coupled to a bosonic continuum even at zero temperature [1]. This is made possible by defining pseudomodes which have a non-Hermitian interaction with the system, and which in isolation are unphysical. We show how they successfully describe the appearance of virtual excitations in the zero-temperature steady-state, which we analyze and bench-mark with the hierarchy-equations-of-motion and the reaction-coordinate approaches. We also discuss new applications of our approach to other types of environments and to error mitigation.

[1] N. Lambert, S. Ahmed, M. Cirio and Franco Nori, Nature Communications 10, 3721 (2019).

*This work was supported by JST PRESTO, JSPS, JST, MEXT, NTT, ARO, AFOSR, AOARD, FQXi, and NSAF.

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Presenters

  • Neill Lambert

    • RIKEN, Japan; and Univ. Michigan, USA
    • RIKEN, Japan

Authors

  • Neill Lambert

    • RIKEN, Japan; and Univ. Michigan, USA
    • RIKEN, Japan

  • Shahnawaz Ahmed

    • Chalmers, Sweden; and RIKEN, Japan
    • Chalmers Univ of Tech
    • Microtechnology and Nanoscience, Chalmers University of Technology, Sweden

  • Mauro Cirio

    • Academy of Engineering Physics, China
    • Graduate School of China Academy of Engineering Physics

  • Franco Nori

    • RIKEN, Japan and Univ. Michigan, USA
    • RIKEN, Japan
    • RIKEN; and Univ. Michigan.
    • RIKEN, Japan; and Univ. Michigan, USA
    • Riken Japan and Univ. Michigan USA
    • RIKEN, Japan and Univ Michigan, USA
    • Theoretical Quantum Physics Laboratory, Department of Physics, RIKEN Cluster for Pioneering Research, The University of Michigan
    • RIKEN and Univ. of Michigan
    • Riken Japan and Univ Michigan USA
    • RIKEN; and University of Michigan
    • RIKEN and Univ. Michigan
    • RIKEN and Univ of Michigan
    • Theoretical Quantum Physics Laboratory, RIKEN Cluster for Pioneering Research, Wako-shi, Saitama 351-0198, Japan
    • RIKEN, and University of Michigan
    • Theoretical Quantum Physics, Riken, Japan
    • RIKEN, Japan; and Univ Michigan, USA
    • Theoretical Quantum Physics Laboratory, RIKEN
    • RIKEN, Japan; Univ. Michigan, USA
    • RIKEN, Japan; Uni. Michigan, USA