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Related papers: Lensing of Dirac monopole in Berry's phase

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The working principle of ordinary refractive lenses can be explained in terms of the space-variant optical phase retardations they introduce, which reshape the optical wavefront curvature and hence affect the subsequent light propagation.…

It is shown that systems described by Harper's equation exhibit a Dirac point at the center of the spectrum whenever the field parameter is a fraction of even denominator. The Dirac point is formed by the touching of two subbands, and the…

Mesoscale and Nanoscale Physics · Physics 2007-08-24 F. Claro

We investigated the properties of dichroic cholesteric liquid crystals (CLCs) being in external static magnetic field directed along helix axis. We have shown that in the case of the wavelength dependence of magneto-optic activity…

Optics · Physics 2023-05-17 A. H. Gevorgyan

A massless Dirac particle is considered, moving along the x-axis while Pauli-coupled by its anomalous magnetic moment to a piecewise constant magnetic field along the same axis, with stochastically varying sign. The motion is approximated…

Quantum Physics · Physics 2012-08-13 A. J. Bracken , D. Ellinas , I. Smyrnakis

Diabolical points, which originate from parameter-dependent accidental degeneracies of a system's energy levels, have played a fundamental role in the discovery of the Berry phase as well as in photonics (conical refraction), in chemical…

Mesoscale and Nanoscale Physics · Physics 2015-02-26 Stefano Chesi , Ying-Dan Wang , Jason Twamley

The Landau free-energy of a compound that benefits from a linear coupling of an electric field and a magnetic field includes a product of the two fields, one polar and time-even and one axial and time-odd. In ME compounds, expectation…

Strongly Correlated Electrons · Physics 2023-05-10 S. W. Lovesey

By analyzing an exactly solvable model in the second quantized formulation which allows a unified treatment of adiabatic and non-adiabatic geometric phases, it is shown that the topology of the adiabatic Berry's phase, which is…

Quantum Physics · Physics 2017-08-23 Kazuo Fujikawa

Gated terahertz cyclotron resonance measurements on epitaxial Bi2Se3 thin films capped with In2Se3 enable the first spectroscopic characterization of a single topological interface state from the vicinity of the Dirac point to above the…

The Dirac monopole is discussed in view of the gauge invariance in Quantum Electrodynamics. It is shown the monopole existence implies the violation of the gauge invariance principle. The monopole field is essentially a longitudinal field…

High Energy Physics - Phenomenology · Physics 2007-05-23 Dario Sassi Thober

Non-trivial Berry phase of graphene leads to unusual quantum correction to the conductivity. Berry phase of pi in single layer graphene (SLG) and 2pi in bi-layer graphene (BLG) is expected to reveal weak anti-localization (WAL) and weak…

Mesoscale and Nanoscale Physics · Physics 2018-10-17 Chandan Kumar , Saurabh Kumar Srivastav , Priyo Adhikary , Sumilan Banerjee , Tanmoy Das , Anindya Das

We consider the adiabatic evolution of the Dirac equation in order to compute its Berry curvature in momentum space. It is found that the position operator acquires an anomalous contribution due to the non Abelian Berry gauge connection…

High Energy Physics - Theory · Physics 2016-08-16 Alain Bérard , Herve Mohrbach

Dirac showed that the existence of one magnetic pole in the universe could offer an explanation for the discrete nature of the electric charge. Magnetic poles appear naturally in most Grand Unified Theories. Their discovery would be of…

High Energy Physics - Phenomenology · Physics 2008-11-26 Luis N. Epele , Huner Fanchiotti , Carlos A. Garcia Canal , Vicente Vento

Graphene bilayers with layer antisymmetric strains are studied using the Dirac-Harper model for a pair of single layer Dirac Hamiltonians coupled by a one-dimensional moir\'e-periodic interlayer tunneling amplitude. This model hosts low…

Mesoscale and Nanoscale Physics · Physics 2021-08-13 Abigail Timmel , E. J. Mele

Massless Dirac fermions occur as low-energy modes in several quasi-two-dimensional condensed matter systems such as graphene, the surface of bulk topological insulators, and in layered organic semiconductors. When the rotational symmetry in…

Mesoscale and Nanoscale Physics · Physics 2015-07-27 Judit Sári , Mark O. Goerbig , Csaba Toke

Graphene-based superlattice (SL) formed by a periodic gap modulation is studied theoretically using a Dirac-type Hamiltonian. Analyzing the dispersion relation we have found that new Dirac points arise in the electronic spectrum under…

Mesoscale and Nanoscale Physics · Physics 2015-06-11 G. M. Maksimova , E. S. Azarova , A. V. Telezhnikov , V. A. Burdov

In this paper we define a non-dynamical phase for a spin-1/2 particle in a rotating magnetic field in the non-adiabatic non-cyclic case, and this phase can be considered as a generalized Berry phase. We show that this phase reduces to the…

Quantum Physics · Physics 2012-12-11 Siamak S. Gousheh , Azadeh Mohammadi , Leila Shahkarami

We consider an all in-fiber optical modulator based on a ring resonator configuration. The case of adiabatic to nonadiabatic transition is considered, where the geometrical (Berry) phase acquired in a round trip along the ring changes…

Quantum Physics · Physics 2007-05-23 Eyal Buks

The presence/absence of a Berry phase depends on the topology of the manifold of dynamical Jahn-Teller potential minima. We describe in detail the relation between these topological properties and the way the lowest two adiabatic potential…

Materials Science · Physics 2009-10-31 Nicola Manini , Paolo De Los Rios

We demonstrate theoretically that using standard external magnetic fields, one can imprint point-like topological defects to the spin texture of a dilute Bose-Einstein condensate. Symmetries of the condensate order parameter render this…

Other Condensed Matter · Physics 2010-03-25 Ville Pietilä , Mikko Möttönen

We use supersymmetry transformations to obtain new one parameter family of inhomogeneous magnetic fields $\mathbf{B} = \widetilde{\mathcal{B}}(x,\lambda) \hat{e}_z$ for which the massless Dirac electron possesses exact solution. The…

Mesoscale and Nanoscale Physics · Physics 2014-07-02 Bikashkali Midya , David J Fernández