We study squeezing in electromagnetic field quadrature components, produced by a collection of A two-level atoms interacting with a single mode of a strong electromagnetic field. We present analytic results both for short and long interaction times. At short times, squeezing grows with the number of atoms for a given initial number of photons. The maximum squeezing which can be achieved in a strong-field case is 66%. At long interaction times, collective effects increase the quadrature fluctuations, compared to the single-atom case. However, for a given number of atoms A, any initial pure atomic state exhibits squeezing when the mean photon number of the initial coherent field satisfies the condition n-bar>(2A ${)}^{4}$ . At times close to the first revival, strong squeezing can be achieved for special initial atomic conditions.We study squeezing in electromagnetic field quadrature components, produced by a collection of A two-level atoms interacting with a single mode of a strong electromagnetic field. We present analytic results both for short and long interaction times. At short times, squeezing grows with the number of atoms for a given initial number of photons. The maximum squeezing which can be achieved in a strong-field case is 66%. At long interaction times, collective effects increase the quadrature fluctuations, compared to the single-atom case. However, for a given number of atoms A, any initial pure atomic state exhibits squeezing when the mean photon number of the initial coherent field satisfies the condition n-bar>(2A${)}^{4}$ . At times close to the first revival, strong squeezing can be achieved for special initial atomic conditions.

Physical Review AMar 1, 199722 citations

Coherent Phase State and Squeezed Phase State

Jeffrey H. Shapiro, Scott Roger Shepard, N. C. Wong

Springer eBooksJan 1, 19904 citations

Coherent entangled state representation for the common eigenvector of p1-p2 and a1+a2 and its characteristics

Hongqi Li, Shi-Min Xu, Xing-Lei Xu +2 more

The new two mode coherent entangled state representation 1p,β〉 is proposed by the technique of integration within an ordered product of operators. Its characteristics and mechanism are analysed. The results show that, the common eigenvector |p,β〉 of p1-p2 and a1+a2 exhibits both the characteristics of the coherent state and entangled state. The 1|p,β〉 makes up a new quantum mechanical representation and possesses the completeness relation. The ideal single-mode squeezed state |p=0〉2=exp［1/2a+22|0〉2 and the vacuum state |0〉1 overlapping on a beam splitter may produce the coherent entangled state |p,β〉at the output by the modulation of the laser field.The new two mode coherent entangled state representation 1p,β〉 is proposed by the technique of integration within an ordered product of operators. Its characteristics and mechanism are analysed. The results show that, the common eigenvector |p,β〉 of p1-p2 and a1+a2 exhibits both the characteristics of the coherent state and entangled state. The 1|p,β〉 makes up a new quantum mechanical representation and possesses the completeness relation. The ideal single-mode squeezed state |p=0〉2=exp［1/2a+22|0〉2 and the vacuum state |0〉1 overlapping on a beam splitter may produce the coherent entangled state |p,β〉at the output by the modulation of the laser field.

Acta Physica SinicaJan 1, 20099 citations

Squeezed Coherent States

Chon‐Fai Kam, Wei-Min Zhang, D.H. Feng

Lecture notes in physicsNov 2, 20220 citations

Atomic and entanglement dynamics in the mixed squeezed coherent state version of the Jaynes-Cummings interaction

Koushik Mandal, Pooja Jethwani, Satyanarayana, M. Venkata

Coherent signal containing squeezed noise in a mixed state of radiation field is considered here as a non-Gaussian mixture of a coherent state density operator and a squeezed state density operator, as opposed to the usual well known squeezed coherent state. Both these states are `quantum' noise-included signal states. Effects of these two distinct ways of adding squeezing to a coherent state are compared and contrasted. The main objective of this work is to study the mixed state version of the Jaynes-Cummings model in the context of a two-level atom interacting with a mixed field state of a squeezed vacuum and a coherent state. The pure squeezed coherent state (PSCS) and the mixed squeezed coherent state (MSCS) are used as the states of the radiation field. The photon-counting distribution (PCD), the atomic inversion and the entanglement dynamics of atom-field interaction for both the radiation fields are investigated and compared with each other. We observe that depending on the state of the field, squeezing has very different effects on coherent photons. Mild squeezing on the coherent photons strongly localizes the PCD for PSCS; however, for MSCS there is no such localization observed - instead squeezing manifests for MSCS as oscillations in the PCD. The effects of squeezing on the atomic inversion and the entanglement dynamics for MSCS are contrasting in comparison with the corresponding quantities associated with PSCS. It is well known in the literature that for PSCS, increasing the squeezing increases the well-known ringing revivals in the atomic inversion, and also increases irregularity in the entanglement dynamics. However, increasing the squeezing in MSCS very significantly alters the collapse-revival pattern in the atomic inversion and the entanglement dynamics of the Jaynes-Cummings model.Coherent signal containing squeezed noise in a mixed state of radiation field is considered here as a non-Gaussian mixture of a coherent state density operator and a squeezed state density operator, as opposed to the usual well known squeezed coherent state. Both these states are `quantum' noise-included signal states. Effects of these two distinct ways of adding squeezing to a coherent state are compared and contrasted. The main objective of this work is to study the mixed state version of the Jaynes-Cummings model in the context of a two-level atom interacting with a mixed field state of a squeezed vacuum and a coherent state. The pure squeezed coherent state (PSCS) and the mixed squeezed coherent state (MSCS) are used as the states of the radiation field. The photon-counting distribution (PCD), the atomic inversion and the entanglement dynamics of atom-field interaction for both the radiation fields are investigated and compared with each other. We observe that depending on the state of the field, squeezing has very different effects on coherent photons. Mild squeezing on the coherent photons strongly localizes the PCD for PSCS; however, for MSCS there is no such localization observed - instead squeezing manifests for MSCS as oscillations in the PCD. The effects of squeezing on the atomic inversion and the entanglement dynamics for MSCS are contrasting in comparison with the corresponding quantities associated with PSCS. It is well known in the literature that for PSCS, increasing the squeezing increases the well-known ringing revivals in the atomic inversion, and also increases irregularity in the entanglement dynamics. However, increasing the squeezing in MSCS very significantly alters the collapse-revival pattern in the atomic inversion and the entanglement dynamics of the Jaynes-Cummings model.

arXiv:2110.14165Oct 27, 20210 citations

Entangled Coherent Stateを用いた推定限界の特性

Dan Murakami

Jan 1, 20120 citations

{)}^{4}

. At times close to the first revival, strong squeezing can be achieved for special initial atomic conditions.