Dissipation, Adaptive Feedback, and New Possibilities for Mixed Quantum Matter with Sagar Vijay скачать в хорошем качестве

Dissipation, Adaptive Feedback, and New Possibilities for Mixed Quantum Matter with Sagar Vijay

Qiskit Quantum Seminar with Sagar Vijay Episode 142 Hosted by Zlatko Minev, PhD. Please feel free to join our public Slack workspace to continue the conversation: http://qisk.it/join-slack Abstract: Quantum simulators provide a setting in which controllable unitary evolution and feedback, in the presence of a dissipative environment, can give rise to mixed states with novel quantum correlations. In this talk, I will discuss examples of how the interplay of these ingredients, specifically the (i) competition between unitary evolution and dissipation, and (ii) measurements and subsequent unitary operations conditioned on the measurement outcomes (“adaptive quantum circuits”), can produce novel mixed-states of quantum matter. I will first show that a one-dimensional quantum many-body system evolving under chaotic unitary dynamics, along with dissipation near its spatial boundary, can be distinct dynamical phases: one in which initially local quantum information in the system is completely lost to the environment, and another in which it is preserved for a parametrically long time. The nature of this transition, and diagnostics for observing these two phases will be discussed. In the second part of my talk, I will present new protocols for adaptive quantum dynamics which can produce mixed states of quantum many-body systems with long-range order or critical behavior, despite coexisting with extensive entropy. I will focus on a specific example, in which a gapped, pure ground-state wavefunction can be converted into a quantum critical mixed-state. Bio: Sagar Vijay is an assistant professor in the physics department at the University of California Santa Barbara (Fall 2020 - Present). He received his A.B. from Princeton University (2013), Ph.D. from the Massachusetts Institute of Technology (2018) and was a Junior Fellow in the Society of Fellows at Harvard University (2018 - 2020), prior to joining UCSB. His research interests are at the interface of quantum condensed matter physics and quantum information science.