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We consider states localized by electrostatic potentials in phosphorene using an atomistic tight binding approach. From the results of the tight-binding calculations of the confined states we extract effective masses for the conduction band…

Mesoscale and Nanoscale Physics · Physics 2020-06-25 B. Szafran

We study the consequences of Entanglement Wedge Nesting for CFTs with holographic duals. The CFT is formulated on an arbitrary curved background, and we include the effects of curvature-squared couplings in the bulk. In this setup we find…

High Energy Physics - Theory · Physics 2020-01-29 Chris Akers , Venkatesa Chandrasekaran , Stefan Leichenauer , Adam Levine , Arvin Shahbazi Moghaddam

The fate of the charge-neutral Dirac point in graphene in a high magnetic field $H$ has been investigated at low temperatures ($T\sim$ 0.3 K). In samples with small $V_0$ (the gate voltage needed to access the Dirac point), the resistance…

Mesoscale and Nanoscale Physics · Physics 2008-05-21 Joseph G. Checkelsky , Lu Li , N. P. Ong

In this paper we consider the novel scenario where a spherically symmetric perfect fluid star is undergoing continual gravitational collapse while continuously radiating energy in an exterior radiating spacetime. There are no trapped…

General Relativity and Quantum Cosmology · Physics 2020-01-08 Rituparno Goswami , Terricia Govender

Graphene's original promise to succeed silicon faltered due to pervasive edge disorder in lithographically patterned deposited graphene and the lack of a new electronics paradigm. Here we demonstrate that the annealed edges in…

We consider a square lattice configuration of circular gate-defined quantum dots in an unbiased graphene sheet and calculate the electronic, particularly spectral properties of finite albeit actual sample sized systems by means of a…

Mesoscale and Nanoscale Physics · Physics 2015-06-19 A. Pieper , R. L. Heinisch , G. Wellein , H. Fehske

One-dimensional lattice with strong spin-orbit interactions (SOI) and Zeeman magnetic field is shown to lead to the formation of a helical charge-density wave (CDW) state near half-filling. Interplay of the magnetic field, SOI constants and…

Mesoscale and Nanoscale Physics · Physics 2015-06-19 E. Nakhmedov , O. Alekperov

Existence of degenerate stationary bound states with square integrable radial wave functions was proved when second-order equations are used with the effective potential of the Reissner-Nordstr\"{o}m (RN) field with two event horizons for…

General Relativity and Quantum Cosmology · Physics 2018-12-06 V. P. Neznamov , I. I. Safronov , V. E. Shemarulin

We derive semiclassical quantization equations for graphene mono- and bilayer systems where the excitations are confined by the applied inhomogeneous magnetic field. The importance of a semiclassical phase, a consequence of the spinor…

Mesoscale and Nanoscale Physics · Physics 2008-08-14 A. Kormanyos , P. Rakyta , L. Oroszlany , J. Cserti

Owing to the Klein tunneling phenomenon, the permanent confinement or localization of electrons within a graphene quantum dot is unattainable. Nonetheless, a constant magnetic field can transiently ensnare an electron within the quantum…

Mesoscale and Nanoscale Physics · Physics 2024-03-26 Mohammed El Azar , Ahmed Bouhlal , Ahmed Jellal

Graphene quantum dots are considered as promising alternatives to quantum dots in III-V semiconductors, e.g., for the use as spin qubits due to their consistency made of light atoms including spin-free nuclei which both imply relatively…

Mesoscale and Nanoscale Physics · Physics 2016-04-20 Markus Morgenstern , Nils Freitag , Aviral Vaid , Marco Pratzer , Marcus Liebmann

Monolayer graphene at charge neutrality in a quantizing magnetic field is a quantum Hall ferromagnet. Due to the spin and valley (near) degeneracies, there is a plethora of possible ground states. Previous theoretical work, based on a…

Mesoscale and Nanoscale Physics · Physics 2023-04-03 Suman Jyoti De , Ankur Das , Sumathi Rao , Ribhu K. Kaul , Ganpathy Murthy

Graphene subjected to chiral-symmetric disorder is believed to host zero energy modes (ZEMs) resilient to localization, as suggested by the renormalization group analysis of the underlying nonlinear sigma model. We report accurate quantum…

Mesoscale and Nanoscale Physics · Physics 2015-09-04 Aires Ferreira , Eduardo R. Mucciolo

We engineer a system of two strongly confined quantum dots to gain reproducible electrostatic control of the spin at zero magnetic field. Coupling the dots in a tight ring-shaped potential with two tunnel barriers, we demonstrate that an…

Symmetry-broken electronic phases support neutral collective excitations. For example, monolayer graphene in the quantum Hall regime hosts a nearly ideal ferromagnetic phase at filling factor $\nu=1$ that spontaneously breaks spin rotation…

We report the existence of confined massless fermion states in a graphene quantum well (QW) by means of analytical and numerical calculations. These states show an unusual quasi-linear dependence on the momentum parallel to the QW: their…

Materials Science · Physics 2007-05-23 J. Milton Pereira , V. Mlinar , F. M. Peeters , P. Vasilopoulos

Fabrication of graphene structures has triggered vast research efforts focused on the properties of two-dimensional systems with massless Dirac fermions. Nevertheless, further progress in exploring this quantum electrodynamics system in…

Mesoscale and Nanoscale Physics · Physics 2009-10-10 P. Neugebauer , M. Orlita , C. Faugeras , A. -L. Barra , M. Potemski

We study electron scattering in graphene quantum dots (GQDs) under the combined influence of a magnetic field, an energy gap, and circularly polarized laser irradiation. Using the Floquet approach and the Dirac equation, we derive the…

Mesoscale and Nanoscale Physics · Physics 2025-01-30 Ahmed Bouhlal , Mohammed El Azar , Aotmane En Naciri , Elmustapha Feddi , Ahmed Jellal

We use holography to prove the Quantum Null Energy Condition (QNEC) at leading order in large-$N$ for CFTs and relevant deformations of CFTs in Minkowski space which have Einstein gravity duals. Given any codimension-2 surface $\Sigma$…

High Energy Physics - Theory · Physics 2016-07-20 Jason Koeller , Stefan Leichenauer

It is shown that the canonical quantum field theory of radiation based on the field theoretical generalization of a recently proposed [1] commutation relation between position and momentum operators of massless particles leads to zero…

Quantum Physics · Physics 2012-12-18 H. Razmi , A. H. Abbassi