Quantum optics with artificial atoms
Doktorsavhandling, 2014

Quantum optics is the study of interaction between atoms and photons. In the eight papers of this thesis, we study a number of systems where artificial atoms (here, superconducting circuits emulating the level structure of an atom) enable us to either improve on known concepts or experiments from quantum optics with natural atoms, or to explore entirely new regimes which have not been possible to reach in such experiments. Paper I shows how unwanted measurement back-action in a parity measurement can be avoided by fully using the information in the measurement record. Paper III is a proof-of-principle experiment demonstrating that an artificial atom built from superconducting circuits can mediate a strong photon-photon interaction. In Papers II and V, we theoretically investigate whether this interaction can be used in a setup for detecting propagating microwave photons, making the photon to be detected impart a phase shift on a coherent probe signal. We find that one atom is not enough to overcome the quantum background noise, but it turns out that several atoms cascaded in the right way can do the trick. In Paper IV, we explain experimental results for a driven artificial atom coupled to photons in a resonator. The last three papers all deal with an artificial atom coupled to a bosonic field at several points, which can be wavelengths apart. Paper VI is a ground-breaking experimental demonstration of coupling between an artificial atom and propagating sound in the form of surface acoustic waves (SAWs). The short SAW wavelength makes the atom "giant" in comparison; the effects of this new regime is explored theoretically in Paper VII, where the multiple coupling points are shown to give interference effects affecting both the atom's relaxation rate and its energy levels. In Paper VIII, an artificial atom in front of a mirror is used to probe the mode structure of quantum vacuum fluctuations.

surface acoustic waves


circuit QED

photon detector

parity measurement

quantum stochastic calculus

Quantum optics

artificial atoms

quantum measurement

Kollektorn, Kemivägen 9, Chalmers
Opponent: Professor Florian Marquardt, Institute for Theoretical Physics II, University of Erlangen-Nuremberg, Germany


Anton Frisk Kockum

Chalmers, Mikroteknologi och nanovetenskap, Tillämpad kvantfysik

Breakdown of the Cross-Kerr Scheme for Photon Counting

Physical Review Letters,; Vol. 110(2013)

Artikel i vetenskaplig tidskrift

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

Designing frequency-dependent relaxation rates and Lamb shifts for a giant artificial atom

Physical Review A - Atomic, Molecular, and Optical Physics,; Vol. 90(2014)p. 013837-

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

Propagating phonons coupled to an artificial atom

Science,; Vol. 346(2014)p. 207-211

Artikel i vetenskaplig tidskrift

Undoing measurement-induced dephasing in circuit QED

Physical Review A - Atomic, Molecular, and Optical Physics,; Vol. 85(2012)

Artikel i vetenskaplig tidskrift

Detailed modelling of the susceptibility of a thermally populated, strongly driven circuit-QED system

Journal of Physics B: Atomic, Molecular and Optical Physics,; Vol. 46(2013)

Artikel i vetenskaplig tidskrift


Nanovetenskap och nanoteknik (SO 2010-2017, EI 2018-)


Atom- och molekylfysik och optik


Den kondenserade materiens fysik



Doktorsavhandlingar vid Chalmers tekniska högskola. Ny serie: 3794

Technical report MC2 - Department of Microtechnology and Nanoscience, Chalmers University of Technology: 291

Kollektorn, Kemivägen 9, Chalmers

Opponent: Professor Florian Marquardt, Institute for Theoretical Physics II, University of Erlangen-Nuremberg, Germany

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