scholarly journals Residual Entropy and Critical Behavior of Two Interacting Boson Species in a Double Well

2017 ◽  
Author(s):  
Fabio Lingua ◽  
Andrea Richaud ◽  
Vittorio Penna
Keyword(s):  
Coherent States ◽  
Variational Approach ◽  
Entanglement Entropy ◽  
Quantum Systems ◽  
Residual Entropy ◽  
Zero Temperature ◽  
Temperature Scenario ◽  
Physical Insight ◽  
Insight Into ◽  
Specific Quantum

Motivated by the importance of entanglement and correlation indicators in the analysis of quantum systems, we study the equilibrium and the residual entropy in a two-species Bose Hubbard dimer when the spatial phase separation of the two species takes place. We consider both the zero and non-zero-temperature regime. We present different kinds of residual entropies (each one associated to a different way of partitioning the system), and we show that they strictly depend on the specific quantum phase characterizing the two species (supermixed, mixed or demixed) even at finite temperature. To provide a deeper physical insight into the zero-temperature scenario, we apply the fully-analytical variational approach based on su(2) coherent states and provide a considerbly good approximation of the entanglement entropy. Finally, we show that the effectiveness of residual entropy as a critical indicator at non-zero temperature is unchanged when considering a restricted combination of energy eigenstates.

Thermodynamics of dissipative coherent states

2021 ◽  
Author(s):  
Antonio Ribeiro Moura ◽  
Pedro Dardengo Mesquita
Keyword(s):  
Coherent State ◽  
Coherent States ◽  
Particle Distribution ◽  
Quantum Systems ◽  
Zero Temperature ◽  
Quantum Harmonic Oscillator ◽  
Harmonic Model ◽  
Specific Frequency ◽  
Almost All ◽  
Thermal States

Abstract Almost all traditional physical formalisms are developed by using conservative forces, and the microscopic implementation of dissipation involves a sort of unusual process, mainly in quantum systems. In this work, we study the quantum harmonic model endowed with a non-Hermitian term responsible for dissipation. In addition, we also include an oscillating field that drives the model to a coherent state, which is dominated by fluctuation in a specific frequency, while regular thermal states are lowlily occupied. The usual coherent state formalism at zero temperature is extended to treat dissipative models at finite temperature. We define a generating function that is used in the evaluation of the most relevant statistical averages, such as the particle distribution. Then, we successfully employ the developed formalism to discuss two well-known applications; the damped quantum harmonic oscillator, and the precession magnetization in a ferromagnetic sample.

scholarly journals Design of a Novel Miniaturized Frequency Selective Surface Based on 2.5-Dimensional Jerusalem Cross for 5G Applications

2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
Peng Zhao ◽  
Yihang Zhang ◽  
Rongrong Sun ◽  
Wen-Sheng Zhao ◽  
Yue Hu ◽  
...  
Keyword(s):  
Resonant Frequency ◽  
Equivalent Circuit ◽  
Equivalent Circuit Model ◽  
Frequency Selective Surface ◽  
Size Reduction ◽  
Two Dimensional ◽  
Physical Insight ◽  
Frequency Selective ◽  
Significant Size ◽  
Insight Into

A compact frequency selective surface (FSS) for 5G applications has been designed based on 2.5-dimensional Jerusalem cross. The proposed element consists of two main parts: the successive segments of the metal traces placed alternately on the two surfaces of the substrate and the vertical vias connecting traces. Compared with previous published two-dimensional miniaturized elements, the transmission curves indicate a significant size reduction (1/26 wavelengths at the resonant frequency) and exhibit good angular and polarization stabilities. Furthermore, a general equivalent circuit model is established to provide direct physical insight into the operating principle of this FSS. A prototype of the proposed FSS has been fabricated and measured, and the results validate this design.

Endwall Blockage in Axial Compressors

1999 ◽  
Vol 121 (3) ◽  
pp. 499-509 ◽  
Author(s):  
S. A. Khalid ◽  
A. S. Khalsa ◽  
I. A. Waitz ◽  
C. S. Tan ◽  
E. M. Greitzer ◽  
...  
Keyword(s):  
Tip Clearance ◽  
Design Parameters ◽  
Tip Clearance Flow ◽  
Axial Compressors ◽  
Clearance Flow ◽  
Flow Features ◽  
Physical Insight ◽  
Level Loading ◽  
Stagger Angle ◽  
Insight Into

This paper presents a new methodology for quantifying compressor endwall blockage and an approach, using this quantification, for defining the links between design parameters, flow conditions, and the growth of blockage due to tip clearance flow. Numerical simulations, measurements in a low-speed compressor, and measurements in a wind tunnel designed to simulate a compressor clearance flow are used to assess the approach. The analysis thus developed allows predictions of endwall blockage associated with variations in tip clearance, blade stagger angle, inlet boundary layer thickness, loading level, loading profile, solidity, and clearance jet total pressure. The estimates provided by this simplified method capture the trends in blockage with changes in design parameters to within 10 percent. More importantly, however, the method provides physical insight into, and thus guidance for control of, the flow features and phenomena responsible for compressor endwall blockage generation.

scholarly journals Entanglement entropy of AdS5 × S5 with massive flavors

2018 ◽  
Vol 33 (03) ◽  
pp. 1850008
Author(s):  
Sen Hu ◽  
Guozhen Wu
Keyword(s):  
Phase Transition ◽  
Line Segment ◽  
Entanglement Entropy ◽  
Point Of View ◽  
Nucl Phys ◽  
Zero Temperature ◽  
Holographic Entanglement Entropy ◽  
Deconfinement Phase Transition

We consider backreacted [Formula: see text] coupled with [Formula: see text] massive flavors introduced by D7 branes. The backreacted geometry is in the Veneziano limit with fixed [Formula: see text]. By dividing one of the directions into a line segment with length l, we get two subspaces. Then we calculate the entanglement entropy between them. With the method of [I. R. Klebanov, D. Kutasov and A. Murugan, Nucl. Phys. B 796, 274 (2008)], we are able to find the cut-off independent part of the entanglement entropy and finally find that this geometry shows no confinement/deconfinement phase transition at zero temperature from the holographic entanglement entropy point of view similar to the case in pure [Formula: see text].

Physical Insight into Self-heating Induced Performance Degradation in RingFET

Silicon ◽  
2021 ◽  
Author(s):  
Sahil Singh ◽  
P. S. T. N. Srinivas ◽  
Arun Kumar ◽  
Pramod Kumar Tiwari
Keyword(s):  
Performance Degradation ◽  
Self Heating ◽  
Physical Insight ◽  
Insight Into

Physical insight into patterned graphene microwave absorber by using transmission matrix method

2018 ◽  
Vol 52 (9) ◽  
pp. 095101
Author(s):  
Song Wu ◽  
Yun He ◽  
Ling Miao ◽  
Junqiang Ai ◽  
Jianjun Jiang
Keyword(s):  
Matrix Method ◽  
Microwave Absorber ◽  
Transmission Matrix ◽  
Physical Insight ◽  
Transmission Matrix Method ◽  
Insight Into

Part I: Physical Insight Into Carbon-Doping-Induced Delayed Avalanche Action in GaN Buffer in AlGaN/GaN HEMTs

2019 ◽  
Vol 66 (1) ◽  
pp. 561-569 ◽  
Author(s):  
Vipin Joshi ◽  
Shree Prakash Tiwari ◽  
Mayank Shrivastava
Keyword(s):  
Carbon Doping ◽  
Physical Insight ◽  
Gan Hemts ◽  
Insight Into
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