Generation of a Population Inversion between Quantum States of a Macroscopic Variable

Autor:	James E. Lukens, Siyuan Han, R. Rouse
Rok vydání:	1996
Předmět:	Physics Thermal equilibrium education.field_of_study Photon Condensed matter physics Population General Physics and Astronomy Intermediate state Absorption (logic) Ground state education Population inversion Energy (signal processing)
Zdroj:	Physical Review Letters. 76:3404-3407
ISSN:	1079-7114 0031-9007
DOI:	10.1103/physrevlett.76.3404
Popis:	A population inversion has been created between the two adjacent fluxoid wells (with energy difference $\ensuremath{\varepsilon}$) in an rf SQUID subject to weak radiation at 100 GHz. The states in the two wells have opposite currents, of magnitude \ensuremath{\sim}2 \ensuremath{\mu}A, circulating through an inductance of 0.2 nH. The steady state population of the upper well ${n}_{u}(\ensuremath{\varepsilon})$ shows local maxima whose positions correspond to calculated photon absorption resonances between the ground state and an intermediate state. The maximum ${n}_{u}(\ensuremath{\varepsilon})$ is 0.94 compared to the expected thermal equilibrium value of ${n}_{u}(\ensuremath{\varepsilon})=2\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}9}$.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::bb4779f8f745577342c240b3239fe0c6 https://doi.org/10.1103/physrevlett.76.3404 Zobrazit plný text záznamu