scholarly journals Observation of twist-induced geometric phases and inhibition of optical tunneling via Aharonov-Bohm effects

2019 ◽  
Vol 5 (1) ◽  
pp. eaau8135 ◽  
Author(s):  
Midya Parto ◽  
Helena Lopez-Aviles ◽  
Jose E. Antonio-Lopez ◽  
Mercedeh Khajavikhan ◽  
Rodrigo Amezcua-Correa ◽  
...  
Keyword(s):  
Geometric Phase ◽  
Berry Phase ◽  
Polarization State ◽  
Guided Wave ◽  
Physical Sciences ◽  
Solid State Physics ◽  
Fiber System ◽  
Geometric Phases ◽  
Photon Tunneling ◽  
Aharonov Bohm

Geometric phases appear ubiquitously in many and diverse areas of the physical sciences, ranging from classical and molecular dynamics to quantum mechanics and solid-state physics. In the realm of optics, similar phenomena are known to emerge in the form of a Pancharatnam-Berry phase whenever the polarization state traces a closed contour on the Poincaré sphere. While this class of geometric phases has been extensively investigated in both free-space and guided wave systems, the observation of similar effects in photon tunneling arrangements has so far remained largely unexplored. Here, we experimentally demonstrate that the tunneling or coupling process in a twisted multicore fiber system can display a chiral geometric phase accumulation, analogous to the Aharonov-Bohm effect. In our experiments, the tunneling geometric phase is manifested through the interference of the corresponding supermodes. Our work provides the first observation of Aharonov-Bohm suppression of tunneling in an optical setting.

BERRY PHASE IN COUPLED TWO-LEVEL SYSTEMS

2013 ◽  
Vol 27 (12) ◽  
pp. 1350088 ◽  
Author(s):  
X. Y. ZHANG ◽  
J. H. TENG ◽  
X. X. YI
Keyword(s):  
Asymptotic Behavior ◽  
Geometric Phase ◽  
Berry Phase ◽  
External Control ◽  
Control Parameters ◽  
Coupling Constant ◽  
Geometric Phases ◽  
Coupled Subsystems ◽  
Two Level Systems ◽  
The Individual

The application of geometric phases into robust control of quantal systems has triggered exploration of the geometric phase for coupled subsystems. Earlier studies have mainly focused on the situation where the external control parameters are in the free Hamiltonian of the subsystems, i.e. the controls exert only on the individual subsystems. Here we consider another circumstance that we can control the coupling geiϕ between the subsystems. By changing only the phase ϕ in the coupling constant, we derive the Berry phase acquired by the system and compare it to the geometric phase acquired by changing the coupling strength g. We find that the asymptotic behavior of the Berry phase depends on the relative Rabi frequency of the two subsystems, and it approaches π when the amplitude of the coupling tends to infinity.

scholarly journals Gravity-Induced Geometric Phases and Entanglement in Spinors and Neutrinos: Gravitational Zeeman Effect

Universe ◽  
2020 ◽  
Vol 6 (10) ◽  
pp. 160
Author(s):  
Banibrata Mukhopadhyay ◽  
Soumya Kanti Ganguly
Keyword(s):  
Electromagnetic Field ◽  
Gravitational Field ◽  
Geometric Phase ◽  
Zeeman Effect ◽  
Relative Strength ◽  
Entangled States ◽  
Neutrino Masses ◽  
Geometric Phases ◽  
Aharonov Bohm ◽  
Gravitational Background

We show Zeeman-like splitting in the energy of spinors propagating in a background gravitational field, analogous to the spinors in an electromagnetic field, otherwise termed the Gravitational Zeeman Effect. These spinors are also found to acquire a geometric phase, in a similar way as they do in the presence of magnetic fields. However, in a gravitational background, the Aharonov-Bohm type effect, in addition to Berry-like phase, arises. Based on this result, we investigate geometric phases acquired by neutrinos propagating in a strong gravitational field. We also explore entanglement of neutrino states due to gravity, which could induce neutrino-antineutrino oscillation in the first place. We show that entangled states also acquire geometric phases which are determined by the relative strength between gravitational field and neutrino masses.

scholarly journals Geometric phases for mixed states of the Kitaev chain

2016 ◽  
Vol 374 (2068) ◽  
pp. 20150231 ◽  
Author(s):  
Ole Andersson ◽  
Ingemar Bengtsson ◽  
Marie Ericsson ◽  
Erik Sjöqvist
Keyword(s):  
Finite Temperature ◽  
Geometric Phase ◽  
Berry Phase ◽  
Condensed Matter ◽  
Order Parameters ◽  
Topological Order ◽  
Mixed States ◽  
Geometric Phases

The Berry phase has found applications in building topological order parameters for certain condensed matter systems. The question whether some geometric phase for mixed states can serve the same purpose has been raised, and proposals are on the table. We analyse the intricate behaviour of Uhlmann's geometric phase in the Kitaev chain at finite temperature, and then argue that it captures quite different physics from that intended. We also analyse the behaviour of a geometric phase introduced in the context of interferometry. For the Kitaev chain, this phase closely mirrors that of the Berry phase, and we argue that it merits further investigation.

Genuine vacuum-induced geometric phases

2015 ◽  
Vol 29 (11) ◽  
pp. 1550043 ◽  
Author(s):  
Minghao Wang ◽  
L. F. Wei ◽  
J. Q. Liang
Keyword(s):  
Excited State ◽  
Quantum Electrodynamics ◽  
Geometric Phase ◽  
Berry Phase ◽  
Cavity Quantum Electrodynamics ◽  
Vacuum Field ◽  
Geometric Phases ◽  
Field System ◽  
The One

Since a pioneer work on vacuum-induced Berry phase (VIBP) was done by Fuentes-Guridi et al. [Phys. Rev. Lett. 89 (2002) 220404], much attention has been paid to the geometric phase effects of vacuum field. However, all the so-called VIBPs investigated previously are not purely vacuum-induced (i.e. the nonvacuum components of the field are also involved). In this paper, we discuss how to deliver geometric phases from the evolution of a genuine vacuum field in a standard cavity quantum electrodynamics (QED) system. First, we design a cyclic evolution of an atom–field system with the atom being initially prepared at the excited state and the field at the genuine vacuum. Then, we calculate the geometric phases acquired during such a cyclic evolution. It is found that such geometric phases are really induced by an evolution of the genuine vacuum field. Specifically, our generic proposal is demonstrated with both the one- and two-mode Jaynes–Cummings model interactions (JCM).

scholarly journals Photonic spin Hall effect in metasurfaces: a brief review

Nanophotonics ◽  
2017 ◽  
Vol 6 (1) ◽  
pp. 51-70 ◽  
Author(s):  
Yachao Liu ◽  
Yougang Ke ◽  
Hailu Luo ◽  
Shuangchun Wen
Keyword(s):  
Hall Effect ◽  
Berry Phase ◽  
Polarization State ◽  
Short Review ◽  
Orbit Interaction ◽  
Spin Hall Effect ◽  
Spin Orbit ◽  
Geometric Phases ◽  
Spin Orbit Interaction ◽  
Space Variant

AbstractThe photonic spin Hall effect (SHE) originates from the interplay between the photon-spin (polarization) and the trajectory (extrinsic orbital angular momentum) of light, i.e. the spin-orbit interaction. Metasurfaces, metamaterials with a reduced dimensionality, exhibit exceptional abilities for controlling the spin-orbit interaction and thereby manipulating the photonic SHE. Spin-redirection phase and Pancharatnam-Berry phase are the manifestations of spin-orbit interaction. The former is related to the evolution of the propagation direction and the latter to the manipulation with polarization state. Two distinct forms of splitting based on these two types of geometric phases can be induced by the photonic SHE in metasurfaces: the spin-dependent splitting in position space and in momentum space. The introduction of Pacharatnam-Berry phases, through space-variant polarization manipulations with metasurfaces, enables new approaches for fabricating the spin-Hall devices. Here, we present a short review of photonic SHE in metasurfaces and outline the opportunities in spin photonics.

scholarly journals Geometric phase for Dirac Hamiltonian under gravitational fields in the nonrelativistic regime

2021 ◽  
pp. 2150090
Author(s):  
Tanuman Ghosh ◽  
Banibrata Mukhopadhyay
Keyword(s):  
Black Hole ◽  
Geometric Phase ◽  
Berry Phase ◽  
Nonrelativistic Limit ◽  
Gravitational Fields ◽  
Schwarzschild Geometry ◽  
Bohm Effect ◽  
The One ◽  
Aharonov Bohm ◽  
Dirac Hamiltonian

We show the appearance of geometric phase in a Dirac particle traversing in nonrelativistic limit in a time-independent gravitational field. This turns out to be similar to the one originally described as a geometric phase in magnetic fields. We explore the geometric phase in the Kerr and Schwarzschild geometries, which have significant astrophysical implications. Nevertheless, the work can be extended to any spacetime background including that of time-dependent. In the Kerr background, i.e. around a rotating black hole, geometric phase reveals both the Aharonov–Bohm effect and Pancharatnam–Berry phase. However, in a Schwarzschild geometry, i.e. around a nonrotating black hole, only the latter emerges. We expect that our assertions can be validated in both the strong gravity scenarios, like the spacetime around black holes, and weak gravity environment around Earth.

scholarly journals The nonadiabatic conditional geometric phase shift in a coiled fiber system

2005 ◽  
Vol 54 (3) ◽  
pp. 1048
Author(s):  
Shen Jian-Qi ◽  
Zhuang Fei
Keyword(s):  
Phase Shift ◽  
Geometric Phase ◽  
Fiber System ◽  
Coiled Fiber

scholarly journals GEOMETRIC PHASES AND QUANTUM PHASE TRANSITIONS

2008 ◽  
Vol 22 (06) ◽  
pp. 561-581 ◽  
Author(s):  
SHI-LIANG ZHU
Keyword(s):  
Phase Transitions ◽  
Geometric Phase ◽  
Quantum Phase Transitions ◽  
Condensed Matter ◽  
Quantum Phase ◽  
Many Body ◽  
Scientific Communities ◽  
Geometric Phases ◽  
Many Body Systems ◽  
The Many

Quantum phase transition is one of the main interests in the field of condensed matter physics, while geometric phase is a fundamental concept and has attracted considerable interest in the field of quantum mechanics. However, no relevant relation was recognized before recent work. In this paper, we present a review of the connection recently established between these two interesting fields: investigations in the geometric phase of the many-body systems have revealed the so-called "criticality of geometric phase", in which the geometric phase associated with the many-body ground state exhibits universality, or scaling behavior in the vicinity of the critical point. In addition, we address the recent advances on the connection of some other geometric quantities and quantum phase transitions. The closed relation recently recognized between quantum phase transitions and some of the geometric quantities may open attractive avenues and fruitful dialogue between different scientific communities.

Geometric phase of cosmological scalar and tensor perturbations in f(R) gravity

2018 ◽  
Vol 33 (14) ◽  
pp. 1850077
Author(s):  
Hamideh Balajany ◽  
Mohammad Mehrafarin
Keyword(s):  
Scalar Field ◽  
Harmonic Oscillator ◽  
Geometric Phase ◽  
Berry Phase ◽  
Time Dependent ◽  
Einstein Theory ◽  
Tensor Perturbations ◽  
Cosmological Scalar ◽  
Conformal Equivalence

By using the conformal equivalence of f(R) gravity in vacuum and the usual Einstein theory with scalar-field matter, we derive the Hamiltonian of the linear cosmological scalar and tensor perturbations in f(R) gravity in the form of time-dependent harmonic oscillator Hamiltonians. We find the invariant operators of the resulting Hamiltonians and use their eigenstates to calculate the adiabatic Berry phase for sub-horizon modes as a Lewis–Riesenfeld phase.

scholarly journals Sub-Geometric Phases in Density Matrices

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Zheng-Chuan Wang
Keyword(s):  
Mixed State ◽  
Geometric Phase ◽  
Density Matrices ◽  
Geometric Phases

Abstract This study presents the generalization of geometric phases in density matrices. We show that the extended sub-geometric phase has an unified expression during the adiabatic or nonadiabatic process and establish the relations between them and the usual Berry or Aharonov-Anandan phases. We also demonstrate the influence of sub-geometric phases on the physical observables. Finally, the above treatment is used to investigate the geometric phase in a mixed state.

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