UMR 8502 Université Paris Sud

Bat 510, 91405 Orsay cedex

2019

S. Rostamzadeh, Adagideli, ıfmmode \dot{I. }\else İ. \fi{}nanıfmmode \mboxç\else ç\fi{}, and Goerbig, M. O., “Large enhancement of conductivity in Weyl semimetals with tilted cones: Pseudorelativity and linear response”, Phys. Rev. B, vol. 100, p. 075438, 2019. Website

2018

K. Yang, Goerbig, M. O., and Doucot, B., “Hamiltonian theory for quantum Hall systems in a tilted magnetic field: Composite-fermion geometry and robustness of activation gaps”, PHYSICAL REVIEW B, vol. 98, p. 205150, 2018.Abstract

We use the Hamiltonian theory developed by Shankar and Murthy to study a quantum Hall system in a tilted magnetic field. With a finite width of the system in the z direction, the parallel component of the magnetic field introduces anisotropy into the effective two-dimensional interactions. The effects of such anisotropy can be effectively captured by the recently proposed generalized pseudopotentials. We find that the off-diagonal components of the pseudopotentials lead to mixing of composite fermions Landau levels, which is a perturbation to the picture of p filled Landau levels in composite-fermion theory. By changing the internal geometry of the composite fermions, such a perturbation can be minimized and one can find the corresponding activation gaps for different tilting angles, and we calculate the associated optimal metric. Our results show that the activation gap is remarkably robust against the in-plane magnetic field in the lowest and first Landau levels.

M. Trushin, Goerbig, M. O., and Belzig, W., “Model Prediction of Self-Rotating Excitons in Two-Dimensional Transition-Metal Dichalcogenides”, PHYSICAL REVIEW LETTERS, vol. 120, p. 187401, 2018.Abstract

Using the quasiclassical concept of Berry curvature we demonstrate that a Dirac exciton-a pair of Dirac quasiparticles bound by Coulomb interactions-inevitably possesses an intrinsic angular momentum making the exciton effectively self-rotating. The model is applied to excitons in two-dimensional transition metal dichalcogenides, in which the charge carriers are known to be described by a Dirac-like Hamiltonian. We show that the topological self-rotation strongly modifies the exciton spectrum and, as a consequence, resolves the puzzle of the overestimated two-dimensional polarizability employed to fit earlier spectroscopic measurements.

0

D. K. Mukherjee, Carpentier, D., and Goerbig, M. O., “{Dynamical conductivity of the Fermi arc and the Volkov-Pankratov states on the surface of Weyl semimetals}”, {PHYSICAL REVIEW B}, vol. {100}.Abstract

{Weyl semimetals are known to host massless surface states called Fermi arcs. These Fermi arcs are the manifestation of the bulk-boundary correspondence in topological matter and thus are analogous to the topological chiral surface states of topological insulators. It has been shown that the latter, depending on the smoothness of the surface, host massive Volkov-Pankratov states that coexist with the chiral ones. Here, we investigate these VP states in the framework of Weyl semimetals, namely their density of states and magneto-optical response. We find the selection rules corresponding to optical transitions which lead to anisotropic responses to external fields. In the presence of a magnetic field parallel to the interface, the selection rules and hence the poles of the response functions are mixed.}

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2. M. O. Goerbig, Montambaux, G., and Piéchon, F., “Measure of Diracness in two-dimensional semiconductors”, 2014. Website

3. P. Stoliar, Rozenberg, M., and et al., “Non-volatile multilevel resistive switching memory cell: A transition metal oxide-based circuit”, IEEE Transactions on CAS II , 2014. Website

4. D. Fiocco, Foffi, G., and Sastry, S., “Persistent memory in athermal systems in deformable energy landscapes”, Physical Review Letters, 2014. Website

5. A. Jagannathan and Duneau, M., “Tight-binding models in a quasiperiodic optical lattice”, International Conference on Quasicrystals CQ12 (Kracow, Poland) . 2014. Website

6. H. H. Wensink and et al., “Differently Shaped Hard Body Colloids in Confinement: From passive to active particles ”, Eur. Phys. J. Special Topics, no. 222, p. 3023, 2013. Website

7. C. P. Moca, Simon, P., and et al., “Finite-frequency-dependent noise of a quantum dot in a magnetic field”, 2013. Website

8. N. Thiebaut, Regnault, N., and Goerbig, M. O., “Fractional quantum Hall states in charge-imbalanced bilayer systems ”, J. Phys.: Conf. Ser. , no. 456, p. 012036 , 2013. Website