160 citations · 1k across the 39 of their papers we have counts for
28 papers · 1 filter
Gap Structure of the Hofstadter System of Interacting Dirac Fermions in Graphene
Vadym Apalkov, Tapash Chakraborty
The effects of mutual Coulomb interactions between Dirac fermions in monolayer graphene on the Hofstadter energy spectrum have been studied. Our studies indicate that the effects o…
Incompressible States of Dirac Fermions in Graphene with Anisotropic Interactions
V. M. Apalkov, Tapash Chakraborty
We report on the properties of incompressible states of Dirac fermions in graphene in the presence of anisotropic interactions and a quantizing magnetic field. We introduce the nec…
Traits and Characteristics of Interacting Dirac fermions in Monolayer and Bilayer Graphene
Tapash Chakraborty, Vadim Apalkov
The relativistic-like behavior of electrons in graphene significantly influences the interaction properties of these electrons in a quantizing magnetic field, resulting in more sta…
The Fractional Quantum Hall Effect of Tachyons in a Topological Insulator Junction
Vadim M. Apalkov, Tapash Chakraborty
We have studied the tachyonic excitations in the junction of two topological insulators in the presence of an external magnetic field. The Landau levels, evaluated from an effectiv…
Superluminal Tachyonlike Excitations of Dirac Fermions in a Topological Insulator Junction
Vadim M. Apalkov, Tapash Chakraborty
We have considered a system of two topological insulators and have determined the properties of the surface states at the junction. Here we report that these states, under certain…
Interacting Dirac Fermions on a Topological Insulator in a Magnetic Field
Vadim M. Apalkov, Tapash Chakraborty
We have studied the fractional quantum Hall states on the surface of a topological insulator thin film in an external magnetic field, where the Dirac fermion nature of the charge c…
A Stable Pfaffian State in Bilayer Graphene
Vadim M. Apalkov, Tapash Chakraborty
Here we show that the Pfaffian state proposed for the fractional quantum Hall states in conventional two-dimensional electron systems can be readily realized in a bilayer…
Misoriented bilayer graphene in a magnetic field: Optical transitions at commensurate angles
Vadim M. Apalkov, Tapash Chakraborty
Misoriented bilayer graphene with commensurate angles shows unique magneto-optical properties. The optical absorption spectra of such a system strongly depend on the angle of rotat…
Signature of valley polarization in fractional flux periodicity of a graphene ring
D. S. L. Abergel, Vadim M. Apalkov, Tapash Chakraborty
We have studied the interplay of valley polarization and the Coulomb interaction on the energy spectrum, persistent current, and optical absorption of a graphene quantum ring. We s…
Collective Excitations of Dirac Electrons in Graphene
Vadim Apalkov, Xue-Feng Wang, Tapash Chakraborty
Two-dimensional electrons in graphene are known to behave as massless fermions with Dirac-Weyl type linear dispersion near the Dirac crossing points. We have investigated the colle…
The Fock-Darwin States of Dirac Electrons in Graphene-based Artificial Atoms
Hong-Yi Chen, Vadim Apalkov, Tapash Chakraborty
We have investigated the Fock-Darwin states of the massless chiral fermions confined in a graphitic parabolic quantum dot. In the light of the Klein tunneling, we have analyzed the…
Spin-Orbit Coupling and Tunneling Current in a Parabolic Quantum Dot
Hong-Yi Chen, Vadim Apalkov, Tapash Chakraborty
We propose a novel approach to explore the properties of a quantum dot in the presence of the spin-orbit interaction and in a tilted magnetic field. The spin-orbit coupling within…
The Fractional Quantum Hall States of Dirac Electrons in Graphene
Vadim M. Apalkov, Tapash Chakraborty
We have investigated the fractional quantum Hall states for the Dirac electrons in a graphene layer in different Landau levels. The relativistic nature of the energy dispersion rel…
Spin transitions in an incompressible liquid Coulomb coupled to a quantum dot
V. M. Apalkov, Tapash Chakraborty, C. Schuller
We report on our investigation of the low-lying energy spectra and charge density of a two-dimensional quantum Hall liquid at that is Coulomb coupled to a quantum dot.…
Interplay of Short-Range Interactions and Quantum Interference Near the Integer Quantum Hall Transition
V. M. Apalkov, M. E. Raikh
Short-range electron-electron interactions are incorporated into the network model of the integer quantum Hall effect. In the presence of interactions, the electrons, propagating a…
Zero-Field Satellites of a Zero-Bias Anomaly
V. M. Apalkov, M. E. Raikh
Spin-orbit (SO) splitting, , of the electron Fermi surface in two-dimensional systems manifests itself in the interaction-induced corrections to the tunneling density o…
Two-phonon scattering of magnetorotons in fractional quantum Hall liquids
V. M. Apalkov, M. E. Portnoi
We study the phonon-assisted process of dissociation of a magnetoroton, in a fractional quantum Hall liquid, into an unbound pair of quasiparticles. Whilst the dissociation is forb…
Electron-phonon interaction in a two-subband quasi-2D system in a quantizing magnetic field
V. M. Apalkov, M. E. Portnoi
We predict a double-resonant feature in the magnetic field dependence of the phonon-mediated mobility of a two-subband quasi-two-dimensional electron system. These resonances take…
Tuning gaps and phases of a two-subband system in a quantizing magnetic field
V. M. Apalkov, M. E. Portnoi
In this work we study the properties of a two-subband quasi-two-dimensional electron system in a strong magnetic field when the electron filling factor is equal to four. When the c…
Two-subband system in quantizing magnetic field: Probing many-body gap by non-equilibrium phonons
V. M. Apalkov, M. E. Portnoi
We study the many-body effects in a two-subband quasi-two-dimensional electron system in a quantizing magnetic field at filling factor three. A manifestation of these effects in th…
Phonon-assisted luminescence of magnetoexcitons in semiconductor quantum wells
V. M. Apalkov, M. E. Portnoi
We consider a line-shape of magnetoexciton photoluminescence from quantum wells when the disorder is sufficiently small. In this case the phonon-assisted optical transitions become…
Intersubband magnetophonon resonances in quantum cascade structures
D. Smirnov, O. Drachenko, J. Leotin +5
We report on our magnetotransport measurements of GaAs/GaAlAs quantum cascade structures in a magnetic field of up to 62 T. We observe novel quantum oscillations in tunneling curre…
Interaction of a quantum dot with an incompressible two-dimensional electron gas
V. M. Apalkov, Tapash Chakraborty
We consider a system of a incompressible quantum Hall liquid in close proximity to a parabolic quantum dot containing a few electrons. We observe a significant influence of the int…
Luminescence Spectra of a Quantum-Dot Cascade Laser
Vadim Apalkov, Tapash Chakraborty
A quantum cascade laser where the quantum wells in the active regions are replaced by quantum dots with their atom-like discrete energy levels is an interesting system to study nov…