RQC Seminar

200th RQC Seminar

• Speaker

  Mr. Michael Tschaffon
  ( Institut für Quantenphysik, Universität Ulm, Germany )

• Date

  16:00-17:00 (4:00 p.m. - 5:00 p.m.), May 21, 2025 (Wednesday)

• Venue

  Hybrid(ZOOM・ Wako Main Research 4F 445-447 Seminar Room / 研究本館4階 セミナー室 (445-447) (C01))

• Title

  Average Correlation as an Indicator for Nonclassicality and Inseparability

• Inquiries

  norilab_rqc_assist[at]ml.riken.jp

Abstract
Ever since their introduction, Bell inequalities have been used to verify nonclassicality of quantum states. In particular, Bell inequalities prove to be suitable to study nonclassicality for discrete variable quantum states. While being a popular tool to test and even quantify nonclassicality, Bell inequalities suffer from being complicated to construct experimentally and cumbersome to evaluate and analyse theoretically. We suggest a solution to this trade-off between accurate predictions and simplicity. For this purpose, we introduce average correlation as a new indicator for nonclassicality. It has both advantages of indicating whether a state is nonclassical, while still being simple to calculate and measure. We show that based on average correlation we obtain new inequalities that can be used to test nonclassicality [1] and inseparability [2] and discuss how average correlation can even be used to classify all bipartite quantum states.

[1] M. E. N. Tschaffon, J. Seiler, M. Freyberger, Average correlation as an indicator for nonclassicality, Phys. Rev. Res. 5 (2023) 023063. URL: https://journals.aps.org/prresearch/abstract/10.1103/PhysRevResearch.5.023063

[2] M. E. N. Tschaffon, J. Seiler, Average correlation as an indicator for inseparability, Phys. Rev. Res. 6 (2024) 013186. URL: https://journals.aps.org/prresearch/abstract/10.1103/PhysRevResearch.6.013186