Speaker: Dr. Anton Frisk Kockum ( Department of Microtechnology and Nanoscience, Chalmers University of Technology, Gothenburg, Sweden

Place: Physics Building 208 

Date and Time: 3:30pm on May 1

Title:  Quantum optics with giant atoms 

Abstract:

In quantum-optics experiments with both natural and artificial atoms, the atoms are usually small enough that they can be approximated as point-like compared to the wavelength of the electromagnetic radiation they interact with. However, superconducting qubits coupled to a meandering transmission line, or to surface acoustic waves [1,2], can realize ”giant" atoms that couple to a bosonic field at several points which are wavelengths apart [3,4]. In this talk, I will describe the physics of both single [3,4] and multiple giant atoms [5]. I will show that single giant atoms have frequency-dependent relaxation rates and Lamb shifts. I will also show that multiple giant atoms can be protected from decohering through the waveguide they couple to, but still have exchange interactions mediated by the waveguide. This is not possible with ”small" atoms. Finally, I will discuss applications of these properties of giant atoms and give an outlook for future studies in this new subfield of quantum optics. 

[1] M. V. Gustafsson et al., Science 346, 207 (2014). 

[2] R. Manenti et al., Nat. Commun. 8, 975 (2017). 

[3] A. F. Kockum et al., Phys. Rev. A 90, 013837 (2014). 

[4] L. Guo et al., Phys. Rev. A 95, 053821 (2017). 

[5] A. F. Kockum et al., Phys. Rev. Lett. 120, 140404 (2018).

Host: Prof. IoChun Hoi