Darkness of two-mode squeezed light in Λ-type atomic system

Moiseev, E. S.; Tashchilina, Arina; Моисеев, С. А.; Lvovsky, A. I.

doi:10.1088/1367-2630/ab5fac

“…By contrast, in the Dicke model, the squeezed vacuum and perfect squeezing are obtained in the ground state, i.e., in the energetically minimal state. Although photon loss (dissipation) can generate quantum entanglement and squeezing in some specially designed driven-dissipative situations 45 , 46 , usually squeezing of flying photons easily diminishes due to photon loss during generation, propagation, and detection and due to noise in the driving laser light, nonlinear crystal, cavity mirrors, etc. 47 .…”

Section: Discussionmentioning

confidence: 99%

Perfect intrinsic squeezing at the superradiant phase transition critical point

Hayashida

¹

,

Makihara

²

,

Peraca

³

et al. 2023

Sci Rep

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Some of the most exotic properties of the quantum vacuum are predicted in ultrastrongly coupled photon–atom systems; one such property is quantum squeezing leading to suppressed quantum fluctuations of photons and atoms. This squeezing is unique because (1) it is realized in the ground state of the system and does not require external driving, and (2) the squeezing can be perfect in the sense that quantum fluctuations of certain observables are completely suppressed. Specifically, we investigate the ground state of the Dicke model, which describes atoms collectively coupled to a single photonic mode, and we found that the photon–atom fluctuation vanishes at the onset of the superradiant phase transition in the thermodynamic limit of an infinite number of atoms. Moreover, when a finite number of atoms is considered, the variance of the fluctuation around the critical point asymptotically converges to zero, as the number of atoms is increased. In contrast to the squeezed states of flying photons obtained using standard generation protocols with external driving, the squeezing obtained in the ground state of the ultrastrongly coupled photon–atom systems is resilient against unpredictable noise.

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“…By contrast, in the Dicke model, the squeezed vacuum and perfect squeezing are obtained in the ground state, i.e, in the energetically minimal state. Although photon loss (dissipation) can generate quantum entanglement and squeezing in some specially designed driven-dissipative situations [49,50], usually squeezing of flying photons easily diminishes due to photon loss during generation, propagation, and detection and due to noise in the driving laser light, nonlinear crystal, cavity mirrors, etc. [51].…”

Section: Discussionmentioning

confidence: 99%

Perfect intrinsic squeezing at the superradiant phase transition critical point

Hayashida

¹

,

Makihara

²

,

Peraca

³

et al. 2022

Preprint

View full text Add to dashboard Cite

Some of the most exotic properties of the quantum vacuum are predicted in ultrastrongly coupled photon–atom systems; one such property is quantum squeezing leading to suppressed quantum fluctuations of photons and atoms. This squeezing is unique because (1) it is realized in the ground state of the system and does not require external driving, and (2) the squeezing can be perfect in the sense that quantum fluctuations of certain observables are completely suppressed. Specifically, we investigate the ground state of the Dicke model, which describes atoms collectively coupled to a single photonic mode, and we found that the photon–atom fluctuation vanishes at the onset of the superradiant phase transition in the thermodynamic limit of an infinite number of atoms. Moreover, when a finite number of atoms is considered, the variance of the fluctuation around the critical point asymptotically converges to zero, as the number of atoms is increased. In contrast to the squeezed states of flying photons obtained using standard generation protocols with external driving, the squeezing obtained in the ground state of the ultrastrongly coupled photon–atom systems is resilient against unpredictable noise.

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“…Noise for |1 ↔ |2 and |1 ↔ |3 are small as the coherence time for the |1 → |2 transition is large and the initial population in level |1 is large [10,29,37]. Moreover, quantum noise induced by the four-wave mixing [38,39] in a Λ scheme are suppressed by presence of a high-Q cavity (κ ω 21 ). Time-reversal character of Eqs.…”

Section: Noisementioning

confidence: 99%

Broadband quantum memory in a cavity via zero spectral dispersion

Moiseev,

Tashchilina,

Moiseev

et al. 2021

Preprint

Self Cite

0

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We seek to design experimentally feasible broadband, temporally multiplexed optical quantum memory with near-term applications to telecom bands. Specifically, we devise dispersion compensation for an impedance-matched narrow-band quantum memory by exploiting Raman processes over two three-level atomic subensembles, one for memory and the other for dispersion compensation. Dispersion compensation provides impedance matching over more than a full cavity linewidth. Combined with one second spin-coherence lifetime the memory could be capable of power efficiency exceeding 90% leading to 10 6 modes for temporal multiplexing. Our design could lead to significant multiplexing enhancement for quantum repeaters to be used for telecom quantum networks.

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Darkness of two-mode squeezed light in Λ-type atomic system

Cited by 7 publications

References 31 publications

Perfect intrinsic squeezing at the superradiant phase transition critical point

Perfect intrinsic squeezing at the superradiant phase transition critical point

Perfect intrinsic squeezing at the superradiant phase transition critical point

Broadband quantum memory in a cavity via zero spectral dispersion

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