Query: Spontaneous Polarization, Spin Current and Quantum Vortices in

Candidate papers:

abstract: We show that how to support propagation of spin degree in a spin symmetric exciton polariton condensates in a semiconductor microcavity. Due to the stimulated spin dependent scattering between hot excitons and condensates, exciton polaritons form a circular polarized condensate with spontaneous breaking the spin rotation symmetry. The spin antiferromagnetic state are developed evidently from the density and spin flow pumped by localized laser source. The low energy spin current is identified where the steady state is characterized by the oscillating spin pattern. We predict via simulation that it is very promising to dynamical creation of fractionalized half quantum vortices induced by effective non abelian gauge potential within currently experiment procedure.
author_names: Bo Xiong
title: Spontaneous Polarization, Spin Current and Quantum Vortices in Exciton Polariton Condensates
year: 2017

abstract: We study the effects of spin orbit interactions on the low energy electronic structure of a single plane of graphene. We find that in an experimentally accessible low temperature regime the symmetry allowed spin orbit potential converts graphene from an ideal two dimensional semimetallic state to a quantum spin Hall insulator. This novel electronic state of matter is gapped in the bulk and supports the transport of spin and charge in gapless edge states that propagate at the sample boundaries. The edge states are nonchiral, but they are insensitive to disorder because their directionality is correlated with spin. The spin and charge conductances in these edge states are calculated and the effects of temperature, chemical potential, Rashba coupling, disorder, and symmetry breaking fields are discussed.
author_names: C L Kane

Eugene J Mele
title: Quantum spin Hall effect in graphene.
venue: Physical review letters
year: 2005

abstract: The quantum spin Hall (QSH) phase is a time reversal invariant electronic state with a bulk electronic band gap that supports the transport of charge and spin in gapless edge states. We show that this phase is associated with a novel Z2 topological invariant, which distinguishes it from an ordinary insulator. The Z2 classification, which is defined for time reversal invariant Hamiltonians, is analogous to the Chern number classification of the quantum Hall effect. We establish the Z2 order of the QSH phase in the two band model of graphene and propose a generalization of the formalism applicable to multiband and interacting systems.
author_names: C L Kane

Eugene J Mele
title: Z2 topological order and the quantum spin Hall effect.
venue: Physical review letters
year: 2005

abstract: Quantum Division The notion of quantum mechanics is that variables are expressed as integer values. In quantum fluids, for instance, vortices are quantized in terms of the polarization and phase shifts observed as multiples of 2p, that is, full rotations of each variable around the vortex core. Theoretical work has predicted that in some instances there should be half quantum vortices, where circumventing the vortex core is characterized by just p rotations of the phase and polarization. By observing exciton polariton condensates Lagoudakis et al. (p. 974) present evidence for the existence of these long predicted half quantum vortices. Evidence is presented for the existence of half quantum vortices in exciton polariton condensates. Singly quantized vortices have already been observed in many systems, including the superfluid helium, Bose Einstein condensates of dilute atomic gases, and condensates of exciton polaritons in the solid state. Two dimensional superfluids carrying spin are expected to demonstrate a different type of elementary excitations referred to as half quantum vortices, characterized by a p rotation of the phase and a p rotation of the polarization vector when circumventing the vortex core. We detect half quantum vortices in an exciton polariton condensate by means of polarization resolved interferometry, real space spectroscopy, and phase imaging. Half quantum vortices coexist with single quantum vortices in our sample.
author_names: Konstantinos G Lagoudakis

Tomas Ostatnicky

Alexey Vitalievich Kavokin

Y G Rubo

Regis Andre

Benoit Deveaud-Pledran
title: Observation of Half Quantum Vortices in an Exciton Polariton Condensate
venue: Science
year: 2009

abstract: The present review analyses and compares various types of dissipationless spin transport: (1) Superfluid transport, when the spin current state is a metastable state (a local but not the absolute minimum in the parameter space) (2) Ballistic spin transport, when spin is transported without losses simply because the sources of dissipation are very weak. (3) Equilibrium spin currents, i.e. genuine persistent currents. (4) Spin currents in the spin Hall effect. Since superfluidity is frequently connected with Bose condensation, recent debates about magnon Bose condensation are also reviewed. For any type of spin currents simplest models were chosen for discussion in order to concentrate on concepts rather than the details of numerous models. The various hurdles on the way of using the concept of spin current (absence of the spin conservation law, ambiguity of spin current definition, etc. were analysed. The final conclusion is that the spin current concept can be developed in a fully consistent manner, and is a useful language for the description of various phenomena in spin dynamics.
author_names: Edouard B Sonin
title: Spin currents and spin superfluidity
year: 2008

abstract: Similar to atoms in cold gases, exciton polaritons in semiconductor microcavities can undergo Bose Einstein condensation, but under non equilibrium conditions. Now, quantized vortices and persistent currents hallmarks of superfluid behaviour have been observed in such condensates.
author_names: Daniele Sanvitto

Francesca M Marchetti

Marzena H Szymanska

Guilherme Tosi

Matthias Baudisch

F Laussy

Dmitry Krizhanovskii

M S Skolnick

Lorenzo Marrucci

Aristide Lemaitre

Jacqueline Bloch

Carlos Tejedor

L Vina
title: Persistent currents and quantized vortices in a polariton superfluid
year: 2010

abstract: We have created vortices in two component Bose Einstein condensates. The vortex state was created through a coherent process involving the spatial and temporal control of interconversion between the two components. Using an interference technique, we map the phase of the vortex state to confirm that it possesses angular momentum. We can create vortices in either of the two components and have observed differences in the dynamics and stability.
author_names: Michael R Matthews

Brian P Anderson

P C Haljan

David S Hall

Carl E Wieman

Eric Allin Cornell
title: Vortices in a Bose Einstein Condensate
year: 1999

abstract: At strong magnetic fields double layer two dimensional electron gas systems can form an unusual broken symmetry state with spontaneous inter layer phase coherence. In this paper we explore the rich variety of quantum and finite temperature phase transitions associated with this broken symmetry. We describe the system using a pseudospin language in which the layer degree of freedom is mapped to a fictional spin 1/2 degree of freedom. With this mapping the spontaneous symmetry breaking is equivalent to that of a spin 1/2 easy plane ferromagnet. In this language spin textures can carry a charge. In particular, vortices carry e/2 electrical charge and vortex antivortex pairs can be neutral or carry charge e. We derive an effective low energy action and use it to discuss the charged and collective neutral excitations of the system. We have obtained the parameters of the Landau Ginzburg functional from first principles estimates and from finite size exact diagonalization studies. We use these results to estimate the dependence of the critical temperature for the Kosterlitz Thouless phase transition on layer separation.
title: Spontaneous interlayer coherence in double layer quantum Hall systems: Charged vortices and Kosterlitz Thouless phase transitions.
venue: Physical review. B, Condensed matter
year: 1995

abstract: Preface 1. Elements of probability theory 2. Random (or stochastic) processes 3. Some useful mathematical techniques 4. Second order coherence theory of scalar wavefields 5. Radiation from sources of any state of coherence 6. Second order coherence theory of vector electromagnetic fields 7. Some applications of second order coherence theory 8. Higher order correlations in optical fields 9. Semiclassical theory of photoelectric detection of light 10. Quantization of the free electromagnetic field 11. Coherent states of the electromagnetic field 12. Quantum correlations and photon statistics 13. Radiation from thermal equilibrium sources 14. Quantum theory of photoelectric detection of light 15. Interaction between light and a two level atom 16. Collective atomic interactions 17. Some general techniques for treating interacting systems 18. The single mode laser 19. The two mode ring laser 20. The linnear light amplifier 21. Squeezed states of light 22. Some quantum effects in nonlinear optics References Author index Subject index.
author_names: Leonard Mandel

Emil Wolf
title: Optical Coherence and Quantum Optics
year: 1995

abstract: 1. Peculiarities of d=1 2. Bosonization 3. Luttinger liquids 4. Refinements 5. Microscopic methods 6. Spin 1/2 chains 7. Interacting fermions on a lattice 8. Coupled fermionic chains 9. Disordered systems 10. Boundaries and isolated impurities 11. Significant others A. Basics of many body B. Not so important fine technical points C. Correlation functions D. Bosonization directory E. Sine Gordon F. Numerical solution
author_names: Thierry Giamarchi
title: Quantum physics in one dimension
year: 2004