Treutlein, Philipp

Date:   Thursday, January 14, 2021
Time:   10:00
Place:   scheduled Zoom meeting
Host:    Klaus Ensslin

Coupling quantum systems with a laser loop

Philipp Treutlein
University of Basel

Many of the breakthroughs in quantum science and technology rely on engineering strong Hamiltonian interactions between quantum systems. Typically, strong coupling relies on short-range forces or on placing the systems in high-quality electromagnetic resonators, which restricts the range of the coupling to short distances. In this talk I will show how a loop of laser light can generate Hamiltonian coupling over a distance [1] and report experiments using this approach to strongly couple a nanomechanical membrane oscillator and an atomic spin ensemble across one meter in a room-temperature environment [2]. We observe spin-membrane normal mode splitting, coherent energy exchange oscillations, two-mode thermal noise squeezing, dissipative coupling with exceptional points, and sympathetic cooling of the membrane. Our experiments demonstrate the versatility and flexibility of light-mediated interactions, a powerful tool for quantum science that offers many further possiblities and is readily applicable to a variety of different systems.

[1] T. M. Karg, B. Gouraud, P. Treutlein, and K. Hammerer, Remote Hamiltonian interactions mediated by light, Phys. Rev. A 99, 063829 (2019).
[2] T. M. Karg, B. Gouraud, C. T. Ngai, G.-L. Schmid, K. Hammerer, and P. Treutlein, Light-mediated strong coupling between a mechanical oscillator and atomic spins one meter apart, Science 369, 6500 174-179 (2020).