Output field squeezing in a weakly-driven dissipative quantum Rabi model

We investigated the optical spin Hall effect (OSHE) of the light field from a closed elliptical metallic curvilinear nanoslit instead of the usual truncated curvilinear nanoslit. By making use of the characteristic bright spots in the light field formed by the noncircular symmetry of the elliptical slit and by introducing a method to separate the incident spin component (ISC) and converted spin component (CSC) of the output field, the OSHE manifested in the spot shifts in the CSC was more clearly observable and easily measurable. The slope of the elliptical slit, which was inverse along the principal axes, provided a geometric phase gradient to yield the opposite shifts of the characteristic spots in centrosymmetry, with a double shift achieved between the spots. Regarding the mechanism of this phenomenon, the flip of the spin angular momentum (SAM) of CSC gave rise to an extrinsic orbital angular momentum corresponding to the shifts of the wavelet profiles of slit elements in the same rotational direction to satisfy the conservation law. The analytical calculation and simulation of finite-difference time domain were performed for both the slit element and the whole slit ellipse, and the evolutions of the spot shifts as well as the underlying OSHE with the parameters of the ellipse were achieved. Experimental demonstrations were conducted and had consistent results. This study could be of great significance for subjects related to the applications of the OSHE.

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Role of Dissipation Characteristics in Predicting Flow from Dissimilar Centrifugal Pumps

Proceedings of the Institution of Mechanical Engineers Part A Journal of Power and Energy ◽

10.1243/pime_proc_1994_208_049_02 ◽

1994 ◽

Vol 208 (4) ◽

pp. 285-294 ◽

Cited By ~ 1

Author(s):

E A Bunt ◽

B Parsons ◽

F Holtzhausen

Keyword(s):

Flow Characteristics ◽

Maximum Flow ◽

Centrifugal Pumps ◽

Graphical Solution ◽

Dissipative Flow ◽

In Series ◽

Lower Maximum ◽

Output Field ◽

High Series

Examination of flows in a particular case of dissimilar pumps coupled in series or in parallel (without check valves) showed that the ‘classical’ graphical solution of combined characteristics in the [+H, +Q] quadrant did not accord with the output field in certain regions. To predict the full flow fields, it was necessary to take into account dissipative flow characteristics in two other quadrants: for low-output parallel flow (when there is still flow available from the pump of higher head when the ‘weaker’ pump's flow has been reduced to zero), that in the [+H, –Q] quadrant; and for high series flow (after the output head of the pump of lower maximum flow has been reduced to zero), that in the [–H, +Q] quadrant. This problem does not arise when the pumps have identical characteristics.

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Algebraic equations for the exceptional eigenspectrum of the generalized Rabi model

Journal of Physics A Mathematical and Theoretical ◽

10.1088/1751-8113/48/45/454005 ◽

2015 ◽

Vol 48 (45) ◽

pp. 454005 ◽

Cited By ~ 8

Author(s):

Zi-Min Li ◽

Murray T Batchelor

Keyword(s):

Algebraic Equations ◽

Rabi Model

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Solution of two-qubit Rabi model with extended generalized rotating-wave approximation

Modern Physics Letters B ◽

10.1142/s0217984921502134 ◽

2021 ◽

pp. 2150213

Author(s):

Zhanyuan Yan ◽

Peihua Qu ◽

BingBing Xu ◽

Shihui Zhang ◽

Jinying Ma

Keyword(s):

Order Approximation ◽

Photon Number ◽

Energy Spectra ◽

Hamiltonian Matrix ◽

Diagonal Form ◽

Coupling Region ◽

Rotating Wave Approximation ◽

Wave Approximation ◽

Rabi Model ◽

Rotating Wave

The generalized rotating-wave approximation (GRWA) method is extended to the two-qubit quantum Rabi model. In the first-order approximation (one photon exchange), the Hamiltonian matrix in photon number space is simplified by introducing two variational parameters. However, the Hamiltonian matrix is not a diagonalizable matrix yet. Furthermore, by presenting a constraint condition on coupling strength and atomic transition frequency, the Hamiltonian matrix is simplified and an effective solvable Hamiltonian with block diagonal form is obtained. In the even and odd parity space, the energy spectra and eigenstates of the two-qubit quantum Rabi model are achieved analytically. Most of the energy spectra, especially the lower energy levels, agree well with the numerical exact results in ultra-strong coupling region, and the ground state wave function can gives a fairly accurate result of mean photon number.

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