Speaker:  Prof. Guin-Dar Lin, National Taiwan University

Time:  1:20 PM,  3/16, 2020

Place:  Room 620, NTHU Physics Department

Title: Vacuum mediated interaction with atoms and superconducting qubits

Abstract:

Understanding ensemble-light interaction has been a fundamental issue for modern quantum technology such as quantum computing and simulation. Atomic systems (including neutral atoms, artificial ones, and trapped ions) are promising platforms for bottom-up quantum state and information manipulation as well as a test bed for many-body physics. In this talk, we discuss the ensemble-vacuum interaction that causes spontaneous processes associated with decay rates and the so-called (collective) Lamb shift. The decay phenomenon and energy shift are two sides of the same coin. We discuss the issues and challenges of the measurement of the induced resonant dipole-dipole interaction in atomic ensembles and superconducting qubit arrays. We report clear visibility of the collective Lamb shift with the help of inserting a mirror to a 1D system. For a 3D atomic cloud, we present two scaling laws of the shift in the forward scattering spectrum.