Adequacy of the Dicke model in cavity QED: A counter-no-go statement

Research output: Contribution to journalArticle

31 Citations (Scopus)

Abstract

The long-standing debate whether the phase transition in the Dicke model can be realized with dipoles in electromagnetic fields is still an unsettled one. The well-known statement often referred to as the "no-go theorem" asserts that the so-called A2 term, missing from the Dicke model, is relevant and prevents the system from undergoing a phase transition. At variance with this common belief, in this paper we prove that the Dicke model does give a proper description of the interaction of light field with the internal excitation of atoms. The phase transition and the spontaneous formation of a transverse-electric mean field cannot be excluded by principle. We point out that the proper treatment of the single-mode approximation is crucial, wherefore we present a systematic derivation of the dipole gauge inside a perfect Fabry-Pérot cavity from first principles. Besides the impact on the debate around the Dicke phase transition, such a cleanup of the theoretical ground of cavity QED is important because currently there are many emerging experimental approaches to reach strong or even ultrastrong coupling between dipoles and photons, which demand a correct treatment of the Dicke model parameters.

Original languageEnglish
Article number053807
JournalPhysical Review A
Volume86
Issue number5
DOIs
Publication statusPublished - Nov 6 2012

Fingerprint

adequacy
counters
cavities
dipoles
emerging
electromagnetic fields
derivation
theorems
photons
approximation
excitation
atoms
interactions

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics

Cite this

Adequacy of the Dicke model in cavity QED : A counter-no-go statement. / Vukics, A.; Domokos, P.

In: Physical Review A, Vol. 86, No. 5, 053807, 06.11.2012.

Research output: Contribution to journalArticle

@article{2416618010864551b2d7e83a21746179,
title = "Adequacy of the Dicke model in cavity QED: A counter-no-go statement",
abstract = "The long-standing debate whether the phase transition in the Dicke model can be realized with dipoles in electromagnetic fields is still an unsettled one. The well-known statement often referred to as the {"}no-go theorem{"} asserts that the so-called A2 term, missing from the Dicke model, is relevant and prevents the system from undergoing a phase transition. At variance with this common belief, in this paper we prove that the Dicke model does give a proper description of the interaction of light field with the internal excitation of atoms. The phase transition and the spontaneous formation of a transverse-electric mean field cannot be excluded by principle. We point out that the proper treatment of the single-mode approximation is crucial, wherefore we present a systematic derivation of the dipole gauge inside a perfect Fabry-P{\'e}rot cavity from first principles. Besides the impact on the debate around the Dicke phase transition, such a cleanup of the theoretical ground of cavity QED is important because currently there are many emerging experimental approaches to reach strong or even ultrastrong coupling between dipoles and photons, which demand a correct treatment of the Dicke model parameters.",
author = "A. Vukics and P. Domokos",
year = "2012",
month = "11",
day = "6",
doi = "10.1103/PhysRevA.86.053807",
language = "English",
volume = "86",
journal = "Physical Review A",
issn = "2469-9926",
publisher = "American Physical Society",
number = "5",

}

TY - JOUR

T1 - Adequacy of the Dicke model in cavity QED

T2 - A counter-no-go statement

AU - Vukics, A.

AU - Domokos, P.

PY - 2012/11/6

Y1 - 2012/11/6

N2 - The long-standing debate whether the phase transition in the Dicke model can be realized with dipoles in electromagnetic fields is still an unsettled one. The well-known statement often referred to as the "no-go theorem" asserts that the so-called A2 term, missing from the Dicke model, is relevant and prevents the system from undergoing a phase transition. At variance with this common belief, in this paper we prove that the Dicke model does give a proper description of the interaction of light field with the internal excitation of atoms. The phase transition and the spontaneous formation of a transverse-electric mean field cannot be excluded by principle. We point out that the proper treatment of the single-mode approximation is crucial, wherefore we present a systematic derivation of the dipole gauge inside a perfect Fabry-Pérot cavity from first principles. Besides the impact on the debate around the Dicke phase transition, such a cleanup of the theoretical ground of cavity QED is important because currently there are many emerging experimental approaches to reach strong or even ultrastrong coupling between dipoles and photons, which demand a correct treatment of the Dicke model parameters.

AB - The long-standing debate whether the phase transition in the Dicke model can be realized with dipoles in electromagnetic fields is still an unsettled one. The well-known statement often referred to as the "no-go theorem" asserts that the so-called A2 term, missing from the Dicke model, is relevant and prevents the system from undergoing a phase transition. At variance with this common belief, in this paper we prove that the Dicke model does give a proper description of the interaction of light field with the internal excitation of atoms. The phase transition and the spontaneous formation of a transverse-electric mean field cannot be excluded by principle. We point out that the proper treatment of the single-mode approximation is crucial, wherefore we present a systematic derivation of the dipole gauge inside a perfect Fabry-Pérot cavity from first principles. Besides the impact on the debate around the Dicke phase transition, such a cleanup of the theoretical ground of cavity QED is important because currently there are many emerging experimental approaches to reach strong or even ultrastrong coupling between dipoles and photons, which demand a correct treatment of the Dicke model parameters.

UR - http://www.scopus.com/inward/record.url?scp=84869022456&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84869022456&partnerID=8YFLogxK

U2 - 10.1103/PhysRevA.86.053807

DO - 10.1103/PhysRevA.86.053807

M3 - Article

AN - SCOPUS:84869022456

VL - 86

JO - Physical Review A

JF - Physical Review A

SN - 2469-9926

IS - 5

M1 - 053807

ER -