QND microwave photon detection and relativistic physics in superconducting circuits

Göran Johansson

Wednesday, 22 May 2013, 15:15
Matfys library

In this presentation, I will address recent advances in the field of microwave quantum optics using superconducting circuits. My first focus will be on the emerging subfield of propagating microwave photonics. This field relies on the fact that the coupling between an artificial superconducting atom (quantum bit) and a microwave photon propagating in a one-dimensional transmission line can be made strong enough to observe quantum coherent effects, without using any cavity to confine the microwave photons. Recent results in this field include the routing of single microwave photons on a nanosecond timescale [1], as well as the observation of anti-bunching in the field reflected from a single artificial atom [2]. In particular, I will discuss the possibility to use the strong cross-Kerr effect observed in these systems [3] to perform quantum non-demolition detection of single microwave photons [4]. In the second part of my presentation, I will turn to the possibility of studying more fundamental physics phenomena in this type of systems. In 1970, Gerald Moore predicted the generation of photons from an oscillating mirror, moving close to the speed of light. The effect was named the dynamical Casimir effect (DCE), from its resemblance to the static Casimir effect. One can study the DCE using a single one-dimensional transmission line terminated with a quickly tunable boundary condition (inductance) [5], and in this system the DCE was after 40 years finally demonstrated experimentally [6]. In particular, I will discuss how to utilise the fast non-dissipative modulation of boundary conditions to experimentally investigate the effect of relativistic motion on the quantum teleportation protocol [7] as well as the twin paradox.

[1] Io-Chun Hoi, C. M. Wilson, G. Johansson, T. Palomaki, B. Peropadre, P. Delsing, Phys. Rev. Lett. 107, 073601 (2011).
[2] Io-Chun Hoi, Tauno Palomaki, Göran Johansson, Joel Lindkvist, Per Delsing and C. M. Wilson, Phys. Rev. Lett. 108, 263601 (2012).
[3] Io-Chun Hoi, C. M. Wilson, Göran Johansson, Tauno Palomaki, Thomas M. Stace, Bixuan Fan, Per Delsing, e-print arXiv:1207.1203
[4] B. Fan, A. F. Kockum, J. Combes, G. Johansson, Io-chun Hoi, C. Wilson, P. Delsing, G. J. Milburn, T. M. Stace, Phys. Rev. Lett. 110, 053601 (2013).
[5] J. R. Johansson, G. Johansson, C. M. Wilson, and Franco Nori, Phys. Rev. Lett. 103, 147003 (2009).
[6] C. M. Wilson, G. Johansson, A. Pourkabirian, M. Simoen, J. R. Johansson, T. Duty, F. Nori and P. Delsing, Nature 479, 376-379 (2011).
[7] Nicolai Friis, Antony R. Lee, Kevin Truong, Carlos Sabín, Enrique Solano, Göran Johansson, Ivette Fuentes, Phys. Rev. Lett. 110, 113602 (2013).