Concept

Dirac sea

Related publications (32)

Spin-Orbital Quantum Liquid on the Honeycomb Lattice

The main characteristic of Mott insulators, as compared to band insulators, is to host low-energy spin fluctuations. In addition, Mott insulators often possess orbital degrees of freedom when crystal-field levels are partially filled. While in the majority ...

2012

Ultrafast photodoping and effective Fermi-Dirac distribution of the Dirac particles in Bi2Se3

Klaus Kern, Marco Grioni, Helmuth Berger, Philippe Bugnon, Alberto Crepaldi

We exploit time- and angle-resolved photoemission spectroscopy to determine the evolution of the out-of-equilibrium electronic structure of the topological insulator Bi2Se3. The response of the Fermi-Dirac distribution to ultrashort IR laser pulses has bee ...

Amer Physical Soc2012

Determination of minimum conductivity of graphene from contactless microwaves measurements

Mihai Adrian Ionescu, Julien Perruisseau-Carrier, Juan Sebastian Gomez Diaz, Pankaj Sharma

We report a non-direct method to determine the minimum conductivity (sigma(min)) of graphene. The proposed technique is based on the prior characterization of graphene sheet impedance at microwave frequencies using waveguides, and on the subsequent extract ...

Ieee2012

Optimizing long-range order, band gap, and group velocities for graphene on close-packed metal surfaces

Harald Brune, Stefano Rusponi, Donat Fabian Natterer

We compare different growth methods with the aim of optimizing the long-range order of a graphene layer grown on Ru(0001). Combining chemical vapor deposition with carbon loading and segregation of the surface layer leads to autocorrelation lengths of 240 ...

2012

Induced Dirac structures on isotropy-type manifolds

Tudor Ratiu, Madeleine Jotz

A new method of singular reduction is extended from Poisson to Dirac manifolds. Then it is shown that the Dirac structures on the strata of the quotient coincide with those of the only other known singular Dirac reduction method. ...

Birkhäuser-Verlag, Springer2011

Singular Reduction Of Dirac Structures

Tudor Ratiu, Madeleine Jotz

The regular reduction of a Dirac manifold acted upon freely and properly by a Lie group is generalized to a nonfree action. For this, several facts about G-invariant vector fields and one-forms are shown. ...

2011

Helical fluctuations in the Raman response of the topological insulator Bi2Se3

Helmuth Berger, Kazimierz Conder

The topological insulator Bi2Se3 shows a Raman-scattering (RS) response related to topologically protected surface states amplified by a resonant interband transition. Most significantly this signal has a characteristic Lorentzian lineshape and spin-helica ...

2011

Dirac Group(oid)s and Their Homogeneous Spaces

Madeleine Jotz

A theorem of Drinfel'd (Drinfel'd (1993)) classifies the Poisson homogeneous spaces of a Poisson Lie group (G,πG) via a special class of Lagrangian subalgebras of the Drinfel'd double of its Lie bialgebra. This result is extended in Liu et al. (1998) to a ...

EPFL2011

Selective adsorption and electronic interaction of F16CuPc on epitaxial graphene

Efthimios Kaxiras, Sheng Meng, Xi Chen, Jun Ren

We investigate the electronic coupling between copper hexadecafluoro-phthalocyanine (F16CuPc) and epitaxial graphene (EG) on 6H-SiC (0001) using a combined approach of low-temperature scanning tunneling spectroscopy and electronic structure calculations. T ...

2010

Asymptotics near ±m of the spectral shift function for Dirac operators with non-constant magnetic fields

We consider a 3-dimensional Dirac operator H_0 with non-constant magnetic field of constant direction, perturbed by a sign-definite matrix-valued potential V decaying fast enough at infinity. Then we determine asymptotics, as the energy goes to +m and -m, ...

2009

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