TY - JOUR

T1 - Photon-induced correlations of quantum systems via an excitation exchange operator

AU - Shuker, Reuben

AU - Koganov, Gennady A.

N1 - Publisher Copyright:
© 2021 Astro Ltd.

PY - 2021/5/1

Y1 - 2021/5/1

N2 - The sensitivities of optical magnetometers, atomic clocks and atom interferometers and other quantum metrology devices, whose signals are linear in the number N of active atoms, have practically arrived at their theoretical limit. Further enhancement of the sensitivities of such devices requires the introduction of new physical processes to improve on their present achievements. Many-body collective correlation among the atoms, spins or, in general, quantum systems may prove to be a suitable method. As such correlations introduce interference terms in the intensity of the scattering amplitudes they may enhance the signal as N(N -1) for N correlated quantum systems. These correlations enhance the signal to noise ratio by a factor of N2 and contribute to better sensitivity in quantum metrology. Moreover, atomic correlation may provide a quantum noise limit, the Heisenberg limit. In the present letter a novel operator is introduced that expresses photon-induced excitation exchange that takes into account energy conservation, Vij = aσiσ j a, where σi = |g) i (e| i is the lowering operator of the i-th atom, and a,a are photon creation and annihilation operators. Here i and j stand for two different atoms. This operator describes real or virtual photon-assisted excitation exchange between two atoms. Moreover, it conserves the total number of excitations in the joint electromagnetic field and the quantum system. A photon-induced excitation exchange between two atoms is calculated and clearly exhibits correlation and collective effects.

AB - The sensitivities of optical magnetometers, atomic clocks and atom interferometers and other quantum metrology devices, whose signals are linear in the number N of active atoms, have practically arrived at their theoretical limit. Further enhancement of the sensitivities of such devices requires the introduction of new physical processes to improve on their present achievements. Many-body collective correlation among the atoms, spins or, in general, quantum systems may prove to be a suitable method. As such correlations introduce interference terms in the intensity of the scattering amplitudes they may enhance the signal as N(N -1) for N correlated quantum systems. These correlations enhance the signal to noise ratio by a factor of N2 and contribute to better sensitivity in quantum metrology. Moreover, atomic correlation may provide a quantum noise limit, the Heisenberg limit. In the present letter a novel operator is introduced that expresses photon-induced excitation exchange that takes into account energy conservation, Vij = aσiσ j a, where σi = |g) i (e| i is the lowering operator of the i-th atom, and a,a are photon creation and annihilation operators. Here i and j stand for two different atoms. This operator describes real or virtual photon-assisted excitation exchange between two atoms. Moreover, it conserves the total number of excitations in the joint electromagnetic field and the quantum system. A photon-induced excitation exchange between two atoms is calculated and clearly exhibits correlation and collective effects.

KW - Collective effects

KW - Quantum correlations

KW - Quantum optics

UR - http://www.scopus.com/inward/record.url?scp=85105658283&partnerID=8YFLogxK

U2 - 10.1088/1612-202X/abf242

DO - 10.1088/1612-202X/abf242

M3 - Article

AN - SCOPUS:85105658283

VL - 18

JO - Laser Physics Letters

JF - Laser Physics Letters

SN - 1612-2011

IS - 5

M1 - 055205

ER -