155 citations · 992 across the 20 of their papers we have counts for
13 papers · 1 filter
Massless multifold Hopf semimetals
Ansgar Graf, Frédéric Piéchon
Three-dimensional topological semimetals exhibit linear energy band crossing points that act as monopoles of Berry curvature. Here, an alternative class of semimetals is introduced…
Dirac points emerging from flat bands in Lieb-kagomé lattices
Lih-King Lim, Jean-Noël Fuchs, Frédéric Piéchon +1
The energy spectra for the tight-binding models on the Lieb and kagomé lattices both exhibit a flat band. We present a model which continuously interpolates between these two limit…
Geometric orbital susceptibility: quantum metric without Berry curvature
Frédéric Piéchon, Arnaud Raoux, Jean-Noël Fuchs +1
The orbital magnetic susceptibility of an electron gas in a periodic potential depends not only on the zero field energy spectrum but also on the geometric structure of cell-period…
Chemical potential asymmetry and quantum oscillations in insulators
Hridis K. Pal, Frédéric Piéchon, Jean-Noël Fuchs +2
We present a theory of quantum oscillations in insulators that are particle-hole symmetric and non-topological but with arbitrary band dispersion, at both zero and non-zero tempera…
Fractal dimensions of the wavefunctions and local spectral measures on the Fibonacci chain
Nicolas Macé, Anuradha Jagannathan, Frédéric Piéchon
We present a theoretical framework for understanding the wavefunctions and spectrum of an extensively studied paradigm for quasiperiodic systems, namely the Fibonacci chain. Our an…
Measure of Diracness in two-dimensional semiconductors
M. O. Goerbig, G. Montambaux, F. Piéchon
We analyze the low-energy properties of two-dimensional direct-gap semiconductors, such as for example the transition-metal dichalcogenides MoS, WS, and their diselenide an…
Inversion Symmetry and Wave-Function-Nodal-Lines of Dirac Electrons in Organic Conductor alpha-(BEDT-TTF)_2I_3
Frédéric Piéchon, Yoshikazu Suzumura
By examining organic conductor alpha-(BEDT-TTF)_2I_3 which is described by a nearest neighbors tight-binding model it is shown that because of inversion symmetry, each component of…
Spin- and valley-dependent magneto-optical properties of MoS2
Félix Rose, M. O. Goerbig, Frédéric Piéchon
We investigate the behavior of low-energy electrons in two-dimensional molybdenum disulfide when submitted to an external magnetic field. Highly degenerate Landau levels form in th…
Existence and merging of Dirac points in -(BEDT-TTF)I organic conductor
Frédéric Piéchon, Yoshikazu Suzumura, Takao Morinari
We reexamine the existence and stability conditions of Dirac points between valence and conduction bands of 3/4 filled -(BEDT-TTF)I conducting plane. We consider the usu…
Distant-Neighbor Hopping in Graphene and Haldane Models
Doru Sticlet, Frédéric Piéchon
Large Chern number phases in a Haldane model become possible if there is a multiplication of Dirac points in the underlying graphene model. This is realized by considering long-dis…
Geometrical engineering of a two-bands Chern insulator in two dimensions with arbitrary topological index
Doru Sticlet, Frederic Piéchon, Jean-Noël Fuchs +2
Two-dimensional 2-bands insulators breaking time reversal symmetry can present topological phases indexed by a topological invariant called the Chern number. Here we first propose…
Emergence of Dirac Electron Pair in Charge Ordered State of Organic Conductor -(BEDT-TTF)I
A. Kobayashi, Y. Suzumura, F. Piéchon +1
We re-examine the band structure of the stripe charge ordered state of -(BEDT-TTF)I under pressure by using an extended Hubbard model within the Hartree mean-field theor…
Universal Scrambling Properties of Spectra and Wave functions in Disordered Interacting Systems
Frédéric Piéchon, Gilles Montambaux
Recent experiments on quantum dots in the Coulomb Blockade regime have shown how adding successive electrons into a dot modifies the energy spectrum and the wave functions of the e…