Quantum optics in superconducting circuits : Generating, engineering and detecting microwave photons
Doktorsavhandling, 2017

Quantum optics in superconducting circuits, known as circuit QED, studies the interaction of photons at microwave frequencies with artificial atoms made of Josephson junctions. Although quite young, remarkable progress has been made in this field over the past decade, especially given the interest in building a quantum computer using superconducting circuits. In this thesis based on the appended papers, we look at generation, engineering and detection of microwave photons using superconducting circuits. We do this by taking advantage of the strong coupling, on-chip tunability and huge nonlinearity available in superconducting circuits. First, we present the strong photon-photon interaction measured experimentally, as shown in the giant cross-Kerr effect. In this work, conditional phase shift of about 20 degrees per photon was measured between two coherent fields at single photon level. Given this strong interaction, we propose and analyze a cascaded setup based on the cross-Kerr effect to detect itinerant microwave photons, a long outstanding problem with only recent experimental realizations. We show that a nondestructive detection of microwave photons is possible with few cascaded transmons. The on-chip tunability of Superconducting Quantum Interference Device (SQUID) is exploited to create a tunable superconducting resonator in the next presented experimental work. Finally, we show that by placing the atom at the end of a transmission line, microwave photons can be generated efficiently and on-demand. We also present a setup that can generate the photons in arbitrary wave packets.

cross-Kerr effect

single photon source

Quantum optics

single photon detector

superconducting circuits

circuit QED

Kollektorn (Room A423), 4th floor, MC2, Kemivägen 9, Göteborg
Opponent: Professor Klaus Mølmer, Department of Physics and Astronomy, Aarhus University, Denmark


Sankar Raman Sathyamoorthy

Chalmers, Mikroteknologi och nanovetenskap (MC2), Tillämpad kvantfysik

Giant Cross–Kerr Effect for Propagating Microwaves Induced by an Artificial Atom

Physical Review Letters,; Vol. 111(2013)p. article nr. 053601-

Artikel i vetenskaplig tidskrift

Detecting itinerant single microwave photons

Comptes Rendus Physique,; Vol. 17(2016)p. 756-765

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Simple, robust, and on-demand generation of single and correlated photons

Physical Review A - Atomic, Molecular, and Optical Physics,; Vol. 93(2016)p. Art. no. 063823-

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Storage and on-demand release of microwaves using superconducting resonators with tunable coupling

Applied Physics Letters,; Vol. 104(2014)p. Art. Nr. 232604-

Artikel i vetenskaplig tidskrift

Quantum Nondemolition Detection of a Propagating Microwave Photon

Physical Review Letters,; Vol. 112(2014)p. art. no. 093601-

Artikel i vetenskaplig tidskrift

Pierre, M., Sathyamoorthy, S.R., Svensson,I.-M., Johansson,G., Delsing.P. Microwave field oscillation and swapping in coupled superconducting resonators.


Atom- och molekylfysik och optik

Annan fysik



Doktorsavhandlingar vid Chalmers tekniska högskola. Ny serie: 4270


Chalmers tekniska högskola

Kollektorn (Room A423), 4th floor, MC2, Kemivägen 9, Göteborg

Opponent: Professor Klaus Mølmer, Department of Physics and Astronomy, Aarhus University, Denmark