Abstract

In this paper, we discuss the connection between two genuinely quantum phenomena—the discontinuity of quantum maximum entropy inference and quantum phase transitions at zero temperature. It is shown that the discontinuity of the maximum entropy inference of local observable measurements signals the non-local type of transitions, where local density matrices of the ground state change smoothly at the transition point. We then propose to use the quantum conditional mutual information of the ground state as an indicator to detect the discontinuity and the non-local type of quantum phase transitions in the thermodynamic limit.

Highlights

  • Quantum phase transitions happen at zero temperature with no classical counterparts and are believed to be driven by quantum fluctuations [22]

  • We propose to solve the problem by using the quantum conditional mutual information of two disconnected parts of the system for the ground states

  • We start from introducing two natural types of quantum phase transitions: a local type that can be detected by a non-smooth change of local observable measurements, and a non-local type which can not

Read more

Summary

Introduction

Quantum phase transitions happen at zero temperature with no classical counterparts and are believed to be driven by quantum fluctuations [22]. Given the observation on the relation between discontinuity of ρ* and the non-local level-crossings, it is natural to consider signaling quantum phase transitions by directly computing where the discontinuity happens. This approach works well in finite systems, but may fail in the thermodynamic limit of infinite size systems as the places of discontinuity (i.e. where the system ‘closes gap’) may change when the system size goes to infinity.

The maximum entropy inference
The examples of two observables
Signaling discontinuity by quantum conditional mutual information
D B1 A DC B2
Further properties of the discontinuity
Summary and discussion

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.