Vacuum structure and PT -symmetry breaking of the non-Hermetian ( iϕ3 ) theory

2017 ◽  
Vol 96 (2) ◽  
Author(s):  
Abouzeid M. Shalaby
Keyword(s):  
Symmetry Breaking ◽  
Pt Symmetry ◽  
Vacuum Structure

scholarly journals Quantum Zeno effects across a parity-time symmetry breaking transition in atomic momentum space

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Tao Chen ◽  
Wei Gou ◽  
Dizhou Xie ◽  
Teng Xiao ◽  
Wei Yi ◽  
...  
Keyword(s):  
Symmetry Breaking ◽  
State Of The Art ◽  
Cold Atom ◽  
Pt Symmetry ◽  
Level System ◽  
Flexible Control ◽  
Time Symmetry ◽  
Symmetry Phase ◽  
Lattice Quantum ◽  
Atomic Momentum

AbstractWe experimentally study quantum Zeno effects in a parity-time (PT) symmetric cold atom gas periodically coupled to a reservoir. Based on the state-of-the-art control of inter-site couplings of atoms in a momentum lattice, we implement a synthetic two-level system with passive PT symmetry over two lattice sites, where an effective dissipation is introduced through repeated couplings to the rest of the lattice. Quantum Zeno (anti-Zeno) effects manifest in our experiment as the overall dissipation of the two-level system becoming suppressed (enhanced) with increasing coupling intensity or frequency. We demonstrate that quantum Zeno regimes exist in the broken PT symmetry phase, and are bounded by exceptional points separating the PT symmetric and PT broken phases, as well as by a discrete set of critical coupling frequencies. Our experiment establishes the connection between PT-symmetry-breaking transitions and quantum Zeno effects, and is extendable to higher dimensions or to interacting regimes, thanks to the flexible control with atoms in a momentum lattice.

scholarly journals Novel thick brane solutions with U(1) symmetry breaking

2021 ◽  
Vol 81 (3) ◽  
Author(s):  
Marzieh Peyravi ◽  
Nematollah Riazi ◽  
Francisco S. N. Lobo
Keyword(s):  
Symmetry Breaking ◽  
Scalar Fields ◽  
Einstein Tensor ◽  
Vacuum Structure ◽  
Different Types ◽  
Dimensional Gravity ◽  
Breaking Parameter ◽  
Symmetry Breaking Term ◽  
The Stability ◽  
Breaking Term

AbstractIn this work, using two scalar fields ($$\phi $$ ϕ , $$\psi $$ ψ ) coupled to 4 + 1 dimensional gravity, we construct novel topological brane solutions through an explicit U(1) symmetry breaking term. The potential of this model is constructed so that two distinct degenerate vacua in the $$\phi $$ ϕ field exist, in analogy to the $$\phi ^{4}$$ ϕ 4 potential. Therefore, brane solutions appear due to the vacuum structure of the $$\phi $$ ϕ field. However, the topology and vacuum structure in the $$\psi $$ ψ direction depends on the symmetry breaking parameter $$\beta ^{2}$$ β 2 , which leads to different types of branes. As a result, one can interpret the present model as a combination of a $$\phi ^{4}$$ ϕ 4 brane with an auxiliary field, which leads to deviations from the $$\phi ^{4}$$ ϕ 4 system with the brane achieving a richer internal structure. Furthermore, we analyse in detail the behaviour of the superpotentials, the warp factors, the Ricci and Kretschmann scalars and the Einstein tensor components. In addition to this, we explore the stability of the brane in terms of the free parameters of the model. The analysis presented here complements previous work and is sufficiently novel to be interesting.

scholarly journals Real-potential-driven anti-PT-symmetry breaking in non-Hermitian Su-Schrieffer-Heeger model

2021 ◽  
Author(s):  
Xuedong Zhao ◽  
Yan Xing ◽  
Lu Qi ◽  
Shutian Liu ◽  
Shou Zhang ◽  
...  
Keyword(s):  
Symmetry Breaking ◽  
Pt Symmetry ◽  
Real Potential

scholarly journals Manifestation of the spontaneous parity-time symmetry breaking phase transition in hot-electron photodetection based on a tri-layered metamaterial

Nanophotonics ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 495-504 ◽  
Author(s):  
Qiang Bai
Keyword(s):  
Phase Transition ◽  
Theoretical Model ◽  
Symmetry Breaking ◽  
Pt Symmetry ◽  
Coupled Mode Theory ◽  
Hot Electron ◽  
Electron Device ◽  
Coupled Mode ◽  
Time Symmetry ◽  
Existence Conditions

AbstractWe theoretically and numerically demonstrate that the spontaneous parity-time (PT) symmetry breaking phase transition can be realized respectively by using two independent tuning ways in a tri-layered metamaterial that consists of periodic array of metal-semiconductor Schottky junctions. The existence conditions of PT symmetry and its phase transition are obtained by using a theoretical model based on the coupled mode theory. A hot-electron photodetection based on the same tri-layered metamaterial is proposed, which can directly show the spontaneous PT symmetry breaking phase transition in photocurrent and possesses dynamical tunability and switchability. This work extends the concept of PT symmetry into the hot-electron photodetection, enriches the functionality of the metamaterial and the hot-electron device, and has varieties of potential and important applications in optoelectronics, photodetection, photovoltaics, and photocatalytics.

Vacuum Structure, Chiral Symmetry Breaking and Radiative Decays of Vector Mesons

1997 ◽  
Vol 06 (01) ◽  
pp. 121-134
Author(s):  
A. R. Panda ◽  
K. C. Roy
Keyword(s):  
Symmetry Breaking ◽  
Chiral Symmetry ◽  
Radiative Decay ◽  
Constituent Quark ◽  
Chiral Symmetry Breaking ◽  
Vector Mesons ◽  
Model Calculations ◽  
Vacuum Structure ◽  
Quark Field ◽  
Decay Widths

The radiative decay widths of vector mesons were considered in a model involving chiral symmetry breaking through a nontrivial vacuum structure where the pion and kaon being treating consistently yield the constituent quark wave functions, approximately the same as that obtained from the gap equations and thus in a way determine the constituent quark field operators. Like its earlier success to some low energy hadronic phenomena, here also the model calculations of radiative decay widths of mesons are in reasonable agreements with other theoretical estimations as well as experimental measurements.

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