Event

Physics Colloquium

  • Speaker  Prof. Yogesh Joglekar

  • Location

    Campus Limpertsberg BS 0.03

    162a, avenue de la Faïencerie

  • Topic(s)
    Physics & Materials Science
  • Type(s)
    In-person event, Lectures and seminars

Non-Hermitian quantum dynamics: super quantum correlations and breaking the quantum speed limit

Abstract:

Quantum theory provides rules governing much of the microscopic world. It dictates a unitary temporal evolution for isolated systems that, when coupled to a large environment, undergo decoherence. Among the counter-intuitive consequences arising from quantum dynamics are spatial and temporal correlations, called Bell or Leggett-Garg (LG) inequalities, that exceed the bounds from local, classical theories. In the simplest system —  a single qubit — quantum temporal correlations are limited to 1.5 for unitary and decohering dynamics. Fundamentally, they are due to limits on the speed at which a quantum state can evolve into an orthogonal one. 

In recent years, quantum systems undergoing coherent but non-unitary evolution have emerged. They are governed by non-Hermitian, parity-time (PT) symmetric Hamiltonians with exceptional point degeneracies. After a short review of how such systems arise in classical and quantum domain, I will present results for PT-symmetry breaking, temporal correlations that exceed the LG bound of 1.5, and quantum state-transfers that exceed the quantum speed limit in a single trapped ion (arXiv:2304.12413).

*Work done with Kater Murch’s group (Washington University), David Allcock group (University of Oregon) and Sourin Das group (IISER, Kolkata).

About the speaker:

Jogesh Joglekar is an experimentally-minded theoretical physicist. After some time in condensed matter physics, he started moonlighting in the area of PT symmetry with the help of high-school students. They have helped him see how PT symmetry emerges in disparate platforms such as a single LC circuit or a vibrating tank of water. His primary area of research is open classical and quantum systems. He usually has far more questions than answers.  

Website: Yogesh N Joglekar Ph.D.: People: People Directory: School of Science: Indiana University Indianapolis (iu.edu)

This year we will continue with the new format:

  • Onsite at Campus Limpertsberg,  where you will have the opportunity to meet the speaker over the lunch. Catering is offered from 12:00 PM to all registered participants (BSC Hall). Talk at 1:00 PM in BSC 0.03
  • Online – through Webex – to give you the opportunity to listen to the talk in case you are travelling or cannot make it onsite at Campus Limpertsberg. Here are the details to join the talk online:

Meeting number: 2784 056 2899

Password: nX9QdqVWZ93

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