Open Quantum Systems: Interplay between the Nano- and Macro- Worlds
The spectacular progress in manipulation of quantum states of matter in the past decades has stimulated a lot of interests in open quantum systems. In this talk, I will cover my recent work on the interplay between the environment and individual quantum objects in two open systems: 1) interacting photons in waveguide-QED systems, and 2) Majorana quantum critical behavior of a resonant level coupled to a dissipative environment. Photon-photon ″bound states″ emerge in a one-dimensional waveguide as a result of the strong coupling to a two-level system. Recent experiments have observed the key signature of those bound state: bunching in the second-order correlation function. Furthermore, I will introduce a two-qubit waveguide-QED system which allows us to access non-Markovian physics in photon-photon correlations. In a dissipative resonant level, a quantum phase transition is observed experimentally, and the scaling laws at the quantum critical point (QCP) are accounted for theoretically by mapping to a Luttinger liquid paradigm. By fine-tuning the system, an anomalous non-Fermi-liquid temperature dependence at the QCP is uncovered, indicating fractionalization of the resonant level into two Majorana quasiparticles.
Host: Jake Taylor