Quantum Entanglement via Thermo Excitation on the Thermo Vacuum State

2019 ◽  
Vol 59 (1) ◽  
pp. 292-299
Author(s):  
Xue-Fen Xu ◽  
Hong-Yi Fan
Keyword(s):  
Quantum Entanglement ◽  
Vacuum State ◽  
Thermo Vacuum State

Evolution of l-photon excited thermo vacuum state in a single-mode damping channel

2016 ◽  
Vol 30 (05) ◽  
pp. 1650009
Author(s):  
Rui He ◽  
Hong-Yi Fan
Keyword(s):  
Laguerre Polynomial ◽  
Hermite Polynomials ◽  
Single Mode ◽  
Vacuum State ◽  
Summation Method ◽  
Squeezing Effect ◽  
Gaussian States ◽  
State Formula ◽  
Non Gaussian ◽  
Thermo Vacuum State

In this paper, we investigate how a kind of non-Gaussian states (l-photon excited thermo vacuum state [Formula: see text]) evolves in a single-mode damping channel. We find that it evolves into a Laguerre-polynomial-weighted real–fictitious squeezed thermo vacuum state, which exhibits strong decoherence and its original nonclassicality fades. In particular, when l = 0, in this damping process the thermo squeezing effect decreases while the fictitious-mode vacuum becomes chaotic. In overcoming the difficulty of calculation, we employ the summation method within ordered product of operators, a new generating function formula about two-variable Hermite polynomials is derived.

Energy distribution in quantized mesoscopic RLC electric circuit

2016 ◽  
Vol 30 (24) ◽  
pp. 1650321
Author(s):  
Wei-Feng Wu ◽  
Hong-Yi Fan
Keyword(s):  
Energy Distribution ◽  
Quantum Information Processing ◽  
Electronic Devices ◽  
Average Energy ◽  
Electric Circuit ◽  
Vacuum State ◽  
Energy Calculation ◽  
Stable Case ◽  
Quantum Statistical ◽  
Thermo Vacuum State

Quantum information processing experimentally depends on optical-electronic devices. In this paper, we consider quantized mesoscopic RLC (resistance, inductance and capacitance) electric circuit in stable case as a quantum statistical ensemble, and calculate energy distribution (i.e. the energy stored in inductance and capacitance as well as the energy consumed on the resistance). For this aim, we employ the technique of integration within ordered product (IWOP) of operator to derive the thermo-vacuum state for this mesoscopic system, with which ensemble average energy calculation is replaced by evaluating expected value in pure state. This approach is concise and the result we deduced is physically appealling.

Thermo Vacuum State for Describing the Density Operator of Photon-subtracted Squeezed Chaotic Light

2017 ◽  
Vol 56 (10) ◽  
pp. 3188-3201
Author(s):  
Zhi-Long Wan ◽  
Hong-Yi Fan ◽  
Heng-Mei Li ◽  
Zhen Wang
Keyword(s):  
Density Operator ◽  
Vacuum State ◽  
Thermo Vacuum State

Quantum disentangling operator and squeezed vacuum state’s noise of a mesoscopic two-loop LC circuit with mutual inductance

2020 ◽  
Vol 34 (12) ◽  
pp. 2050121
Author(s):  
Hong-Yi Fan ◽  
Xiang-Guo Meng
Keyword(s):  
Energy Level ◽  
Quantum Entanglement ◽  
Characteristic Frequency ◽  
Quantum Noise ◽  
Vacuum State ◽  
Mutual Inductance ◽  
Physical Processes ◽  
Squeezed Vacuum State ◽  
Squeezed Vacuum ◽  
Lc Circuit

Quantum disentanglement refers to the transformation of entangled quantum system into disentangled system via some physical processes. In this paper, we search for quantum disentangling operator for the mesoscopic two-loop [Formula: see text] circuit with mutual inductance [Formula: see text]. It is this mutual inductance that causes quantum entanglement. By virtue of the method of integration within ordered product (IWOP) of operators, we find the disentangling operator and deduce the energy level (characteristic frequency). The quantum noise expression of squeezed vacuum state is also derived based on which we see that the large number of quantum entanglement engendered by the mutual inductance is, the more quantum noise produces in the mesoscopic circuit.

scholarly journals WIGNER FUNCTIONS OF THERMO NUMBER STATE, PHOTON SUBTRACTED AND ADDED THERMO VACUUM STATE AT FINITE TEMPERATURE

2009 ◽  
Vol 24 (28) ◽  
pp. 2263-2274 ◽  
Author(s):  
LI-YUN HU ◽  
HONG-YI FAN
Keyword(s):  
Finite Temperature ◽  
Vacuum State ◽  
Statistical Properties ◽  
Wigner Functions ◽  
New Approach ◽  
Number State ◽  
Thermo Field Dynamics ◽  
Thermo Vacuum State

Based on Takahashi–Umezawa thermo field dynamics and the order-invariance of Weyl ordered operators under similar transformations, we present a new approach to derive the exact Wigner functions of thermo number state, photon subtracted and added thermo vacuum state. We find that these Wigner functions are related to the Gaussian–Laguerre type functions of temperature, whose statistical properties are then analyzed.

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