研究実績の概要 |
I have made progress on two works related to this project. In the first, I have studied a situation in which non-Markovian dynamics associated with the continuum threshold (waveguide cut-off mode, for example) in quantum systems can be enhanced by using the properties of a so-called Bound State in Continuum (BIC). A bound state in continuum should be understood as an interference effect that occurs in quantum systems such that the exponential decay associated with the usual resonance is suppressed. In Ref. [1] I have shown that by preparing the system in an initial state that lies orthogonal to the BIC, one can avoid both the exponential decay associated with a resonance as well as the stability associated with the BIC itself to obtain non-Markovian decay on all timescales.
For the second project, I gave a virtual talk based on work demonstrating non-Markovian dynamics influenced by an anomalous exceptional point (EP) appearing at the threshold quite generally in 1-D systems, such as a quantum emitter traveling in an electromagnetic waveguide. An EP is a point in the parameter space of a given open quantum system at which two eigenstates coalesce. We showed this EP gives rise to an unusual non-Markovian dynamics in the form of a power law with a fractional exponent, which gives an opportunity for micro control.
[1] Phys. Rev. A 99, 010102R (2019) [2] S. Garmon, American Physical Society March Meeting 2020, virtual presentation, https://virtualmarchmeeting.com/presentations/anomalous-exceptional-point-and-non-markovian-purcell-effect-at-threshold-in-1-d-continuum-systems
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