Resolving Vacuum Fluctuations in an Electrical Circuit by Measuring the Lamb Shift

Autor:	Johannes M. Fink, Peter Leek, M. Baur, Andreas Fragner, Alexandre Blais, M. Göppl, Andreas Wallraff, R. Bianchetti
Rok vydání:	2008
Předmět:	Physics Flux qubit QED vacuum Multidisciplinary Photon Charge qubit Vacuum state Quantum Physics 01 natural sciences 010305 fluids & plasmas Lamb shift Phase qubit Quantum electrodynamics Quantum mechanics Qubit 0103 physical sciences 010306 general physics
Zdroj:	Science. 322:1357-1360
ISSN:	1095-9203 0036-8075
DOI:	10.1126/science.1164482
Popis:	Quantum theory predicts that empty space is not truly empty. Even in the absence of any particles or radiation, in pure vacuum, virtual particles are constantly created and annihilated. In an electromagnetic field, the presence of virtual photons manifests itself as a small renormalization of the energy of a quantum system, known as the Lamb shift. We present an experimental observation of the Lamb shift in a solid-state system. The strong dispersive coupling of a superconducting electronic circuit acting as a quantum bit (qubit) to the vacuum field in a transmission-line resonator leads to measurable Lamb shifts of up to 1.4% of the qubit transition frequency. The qubit is also observed to couple more strongly to the vacuum field than to a single photon inside the cavity, an effect that is explained by taking into account the limited anharmonicity of the higher excited qubit states.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::54a3e33ee3aef2cd594b67c080a25269 https://doi.org/10.1126/science.1164482 Zobrazit plný text záznamu Plný text ve formátu PDF