Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

中国物理B：英文版

Thermal vacuum state corresponding to squeezed chaotic light and its application

M LONG, 范洪义, 王震

Published Jan 1, 2015• 0 citations
OpenAlex

Abstract

For the density operator(mixed state) describing squeezed chaotic light(SCL) we search for its thermal vacuum state(a pure state) in the real-fictitious space. Using the method of integration within ordered product(IWOP) of operators we find that it is a kind of one- and two-mode combinatorial squeezed state. Its application in evaluating the quantum fluctuation of photon number reveals: the stronger the squeezing is, the larger a fluctuation appears. The second-order degree of coherence of SCL is also deduced which shows that SCL is classic. The new thermal vacuum state also helps to derive the Wigner function of SCL.

Related papers

Thermal vacuum state corresponding to squeezed chaotic light and its application

Zhi-Long Wan, Hong-Yi Fan, Zhen Wang

For the density operator (mixed state) describing squeezed chaotic light (SCL) we search for its thermal vacuum state (a pure state) in the real-fictitious space. Using the method of integration within ordered product (IWOP) of operators we find that it is a kind of one- and two-mode combinatorial squeezed state. Its application in evaluating the quantum fluctuation of photon number reveals: the stronger the squeezing is, the larger a fluctuation appears. The second-order degree of coherence of SCL is also deduced which shows that SCL is classic. The new thermal vacuum state also helps to derive the Wigner function of SCL.

Chinese Physics B•Dec 1, 2015•6 citations

Thermo vacuum state for Gaussian-enhanced chaotic light

Weifeng Wu, Hong-Yi Fan

In nature, there exists superposition of Gaussian light and chaotic light, so we introduce the density operator for describing the Gaussian-enhanced chaotic light (GECL). By virtue of the method of integration within ordered product (IWOP) of operators, we derive its normalization constant. Then, by virtue of the partial trace method, we derive its thermo vacuum state and this may greatly simplify the calculation of photon number average and quantum fluctuation in GECL. It is demonstrated that the second-order degree of coherence of GECL is larger than 2.

Modern Physics Letters B•May 10, 2017•1 citation

New light fields based on integration theory within the Weyl ordering product of operators

Ke Zhang, Lanlan Li, Da-wei Guo +1 more

The development of quantum optics theory based on the method of integration within an ordered product of operators (IWOP) has greatly stimulated the study of quantum states in the light field, especially non-Gaussian states with various non-classical properties. In this paper, the two-mode squeezing operator is derived with integral theory within the Weyl ordering product of operators using a combinatorial field in which one mode is a chaotic field and the other mode is a vacuum field. The density operator of the new light field, its entanglement property and photon number distribution are analyzed. We also note that tracing a three-mode pure state can yield this new light field. These methods represent a theoretical approach to investigating new density operators of light fields.

Chinese Physics B•Jul 5, 2022•4 citations

Quantum Nature of Light in Displaced Squeezed Chaotic State

Sitotaw Eshete

In this work the squeezing and statistical properties for single-mode displaced squeezed chaotic state is analyzed with the help of the density operator for a single-mode light.It is found that the effect of the thermal light is to reduce the quadrature squeezing but increases the mean photon number.According to the generated results of analyzing the quadrature squeezing, the system has 98.17% of squeezing (in squeezed state) in which the system initial to be in vacuum state (no photon at all) and occurs at the squeeze parameter ( = 2).In addition, the squeeze parameter enhances both the quadrature squeezing and the mean photon number.

Advances in physics theories and applications•Jan 1, 2018•0 citations

Statistical properties of the squeezing-enhanced thermal state

Shuai Wang, Hong-Yi Fan

We introduce a new (to our best knowledge) type of squeezing-enhanced thermal states (SETS) that is generated by operating a new two-parameter generalized squeezing operator on a thermal (chaotic) field. By using the operator’s Weyl-ordering invariance under the similarity transformation and the Weyl correspondence scheme, we derive the normally ordered form of the density operator of SETS. Based on it, we study the resulting squeezing effects of the SETS and investigate its statistical properties by the second-order correlation function, photon-number distribution, and the Wigner function. Compared with the usual squeezed thermal state, SETS exhibits stronger squeezing and some new statistical properties. We find that the effect of the new type of squeezing operator is rotated squeezing.

Journal of the Optical Society of America B•Dec 9, 2011•12 citations

Higher-order squeezing properties of two-mode squeezed states

Jiaxin Gong, P. K. Aravind

We have investigated the properties of two-mode squeezed states of various kinds: squeezed coherent states, squeezed number states, squeezed thermal states, and squeezed number-thermal states. The properties studied include characteristic functions, photon number distributions, and high-order moments. We show that a two-mode squeezed coherent state appears in either of its modes as a Glauber-Lachs superposition of a coherent signal with thermal noise; this generalizes the well-known thermofield result that a two-mode squeezed vacuum state behaves like a pure thermal state in either of its modes. We investigate the higher-order squeezing (in the sense of Hong and Mandel) of squeezed coherent-thermal and squeezed number-thermal states. Although the squeezing is found to increase with order in both cases, there are nevertheless interesting differences that can be traced to the fact that the Wigner function has a Gaussian form for the former but not for the latter.

Annual Meeting Optical Society of America•Jan 1, 1990•0 citations
For the density operator(mixed state) describing squeezed chaotic light(SCL) we search for its thermal vacuum state(a pure state) in the real-fictitious space. Using the method of integration within ordered product(IWOP) of operators we find that it is a kind of one- and two-mode combinatorial squeezed state. Its application in evaluating the quantum fluctuation of photon number reveals: the stronger the squeezing is, the larger a fluctuation appears. The second-order degree of coherence of SCL is also deduced which shows that SCL is classic. The new thermal vacuum state also helps to derive the Wigner function of SCL.
For the density operator (mixed state) describing squeezed chaotic light (SCL) we search for its thermal vacuum state (a pure state) in the real-fictitious space. Using the method of integration within ordered product (IWOP) of operators we find that it is a kind of one- and two-mode combinatorial squeezed state. Its application in evaluating the quantum fluctuation of photon number reveals: the stronger the squeezing is, the larger a fluctuation appears. The second-order degree of coherence of SCL is also deduced which shows that SCL is classic. The new thermal vacuum state also helps to derive the Wigner function of SCL.
In nature, there exists superposition of Gaussian light and chaotic light, so we introduce the density operator for describing the Gaussian-enhanced chaotic light (GECL). By virtue of the method of integration within ordered product (IWOP) of operators, we derive its normalization constant. Then, by virtue of the partial trace method, we derive its thermo vacuum state and this may greatly simplify the calculation of photon number average and quantum fluctuation in GECL. It is demonstrated that the second-order degree of coherence of GECL is larger than 2.
The development of quantum optics theory based on the method of integration within an ordered product of operators (IWOP) has greatly stimulated the study of quantum states in the light field, especially non-Gaussian states with various non-classical properties. In this paper, the two-mode squeezing operator is derived with integral theory within the Weyl ordering product of operators using a combinatorial field in which one mode is a chaotic field and the other mode is a vacuum field. The density operator of the new light field, its entanglement property and photon number distribution are analyzed. We also note that tracing a three-mode pure state can yield this new light field. These methods represent a theoretical approach to investigating new density operators of light fields.
In this work the squeezing and statistical properties for single-mode displaced squeezed chaotic state is analyzed with the help of the density operator for a single-mode light.It is found that the effect of the thermal light is to reduce the quadrature squeezing but increases the mean photon number.According to the generated results of analyzing the quadrature squeezing, the system has 98.17% of squeezing (in squeezed state) in which the system initial to be in vacuum state (no photon at all) and occurs at the squeeze parameter ( = 2).In addition, the squeeze parameter enhances both the quadrature squeezing and the mean photon number.
We introduce a new (to our best knowledge) type of squeezing-enhanced thermal states (SETS) that is generated by operating a new two-parameter generalized squeezing operator on a thermal (chaotic) field. By using the operator’s Weyl-ordering invariance under the similarity transformation and the Weyl correspondence scheme, we derive the normally ordered form of the density operator of SETS. Based on it, we study the resulting squeezing effects of the SETS and investigate its statistical properties by the second-order correlation function, photon-number distribution, and the Wigner function. Compared with the usual squeezed thermal state, SETS exhibits stronger squeezing and some new statistical properties. We find that the effect of the new type of squeezing operator is rotated squeezing.
We have investigated the properties of two-mode squeezed states of various kinds: squeezed coherent states, squeezed number states, squeezed thermal states, and squeezed number-thermal states. The properties studied include characteristic functions, photon number distributions, and high-order moments. We show that a two-mode squeezed coherent state appears in either of its modes as a Glauber-Lachs superposition of a coherent signal with thermal noise; this generalizes the well-known thermofield result that a two-mode squeezed vacuum state behaves like a pure thermal state in either of its modes. We investigate the higher-order squeezing (in the sense of Hong and Mandel) of squeezed coherent-thermal and squeezed number-thermal states. Although the squeezing is found to increase with order in both cases, there are nevertheless interesting differences that can be traced to the fact that the Wigner function has a Gaussian form for the former but not for the latter.