arXiv subjects

O. Tsyplyatyev

Publications and source records attributed to O. Tsyplyatyev.

22 records · Page 2Linked to original sources

arXiv2007

Characterization of graphene through anisotropy of constant-energy maps in angle-resolved photoemission

We show theoretically how constant-energy maps of the angle-resolved photoemission intensity can be used to test wave function symmetry in graphene. For monolayer graphene, we demonstrate that the observed anisotropy of ARPES spectra is a manifestation of what has been recently branded as electronic chirality. For bilayer graphene, we show that the anisotropy of the constant-energy maps may be used to extract information about the magnitude and sign of interlayer coupling parameters and about symmetry breaking inflicted on a bilayer by the underlying substrate.

cond-mat.mes-hall↗

arXiv2006

Thermally excited spin-current in metals with embedded ferromagnetic nanoclusters

We show that a thermally excited spin-current naturally appears in metals with embedded ferromagnetic nanoclusters. When such materials are subjected to a magnetic field, a spin current can be generated by a temperature gradient across the sample as a signature of electron-hole symmetry breaking in a metal due to the electron spin-flip scattering from polarised magnetic moments. Such a spin current can be observed via a giant magneto-thermopower which tracks the polarisation state of the magnetic subsystem and is proportional to the magnetoresistance. Our theory explains the recent experiment on Co clusters in copper by S. Serrano-Guisan \textit{et al} [Nature Materials AOP, doi:10.1038/nmat1713 (2006)]

cond-mat.mtrl-sci↗

arXiv2005

Magnetoresistance in metals with embedded magnetic nano-clusters

We propose a kinetic theory of transport in metals embedded with ferromagnetic nanoclusters, describing the dependence of the form of magnetoresistance on anisotropy characteristics of the ensemble of clusters and the influence of the electron spin depolarisation by clusters. We note that this effect is strongest when all the clusters have the same intrinsic easy-axis anisotropy.

cond-mat.mtrl-sci↗

arXiv2003

On the Applicability of the Ergodicity Hypothesis to Mesoscopic Fluctuations

We evaluate a typical value of higher order cumulants (irreducible moments) of conductance fluctuations that could be extracted from magneto-conductance measurements in a single sample when an external magnetic field is swept over an interval $B_0$. We find that the n-th cumulant has a sample-dependent random part $\pm \gN 2^{n/2}\sqrt{a_{n}B_{c}/B_{0}}$, where $\gN 2$ is the variance of conductance fluctuations, $B_{c}$ is a correlation field, and $a_{n}\sim n!$. This means that an apparent deviation of the conductance distribution from a Gaussian shape, manifested by non-vanishing higher cumulants, can be a spurious result of correlations of conductances at different values of the magnetic field.

cond-mat.mes-hall↗