arXiv subjects

Ludvik Smrcka

Publications and source records attributed to Ludvik Smrcka.

6 recordsLinked to original sources

arXiv2015

Commensurability oscillations in a quasi-two-dimensional electron gas subjected to strong in-plane magnetic field

We report on a theoretical study of the commensurability oscillations in a quasi-two-dimensional electron gas modulated by a unidirectional periodic potential and subjected to tilted magnetic fields with a strong in-plane component. As a result of coupling of the in-plane field component and the confining potential in the finite-width quantum well, the originally circular cyclotron orbits become anisotropic and tilted out of the sample plane. A quasi-classical approach to the theory, that relates the magneto-resistance oscillations to the guiding-center drift, is extended to this case.

cond-mat.mes-hall↗

arXiv2011

Tight-binding description of Landau levels of graphite in tilted magnetic fields

The electronic structure of Bernal-stacked graphite subject to tilted magnetic fields is studied theoretically. The minimal nearest-neighbor tight-binding model with the Peierls substitution is employed to describe the structure of Landau levels. We show that while the orbital effect of the in-plane component of the magnetic field is negligible for massive Dirac fermions in the vicinity of the K point of the graphite Brillouin zone, at the H point it leads to the experimentally observable splitting of Landau levels, which grows approximately linearly with the in-plane field intensity.

cond-mat.mes-hall↗

arXiv2011

Electronic properties of graphite in tilted magnetic fields

The minimal nearest-neighbor tight-binding model with the Peierls substitution is employed to describe the electronic structure of Bernal-stacked graphite subject to tilted magnetic fields. We show that while the presence of the in-plane component of the magnetic field has a negligible effect on the Landau level structure at the K point of the graphite Brillouin zone, at the H point it leads to the experimentally observable splitting of Landau levels which grows approximately linearly with the in-plane field intensity.

cond-mat.mes-hall↗

arXiv2003

Cyclotron Resonance Study of the Two-Dimensional Electron Layers and Double-Layers in Tilted Magnetic Fields

The far-infrared absorption in two-dimensional electron layers subject to magnetic field of general orientation was studied theoretically. The Kubo formula is employed to derive diagonal components of the magneto-conductivity tensor of two-dimensional electron single-layers and double-layers. The parabolic quantum well is used to model a simple single-layer system. Both single-layer and double-layer systems can be realized in a pair of tunnel-coupled, strictly two-dimensional quantum wells. Obtained results are compared to experimental data.

cond-mat.mes-hall↗

arXiv2002

Tight-binding model for strongly modulated two-dimensional superlattices

Common models describing magnetotransport properties of periodically modulated two--dimensional systems often either directly start from a semiclassical approach or give results well conceivable within the semiclassical framework. Recently, magnetoresistance oscillations have been found on samples with strong unilateral modulation and short period (d=15 nm) which cannot be explained on a semiclassical level (magnetic breakdown). We use a simple fully quantum mechanical model which gives us both magnetoresistance data nicely comparing to the experiments and a good intuitive insight into the effects taking place in the system.

cond-mat.mes-hall↗

arXiv2002

Magnetoresistance calculations for a two-dimensional electron gas with unilateral short-period strong modulation

The linear response theory is used to describe magnetoresistance oscillations of short-period unilateral superlattices with strong modulation (or alternatively arrays of coupled quantum wires). The semiclassical description of this system fails for strong magnetic fields (magnetic breakdown) and we employ a simple fully-quantum-mechanical tight-binding model in conjunction with Kubo's formula instead. The resulting magnetoresistance data nicely compare to the experiments while the model opens good intuitive insight into the effects taking place in the system.

cond-mat.mes-hall↗