Searcharxiv⌕ Search

arXiv subjects

Tutul Biswas

Publications and source records attributed to Tutul Biswas.

21 records · Page 2Linked to original sources

Acoustic phonon-limited resistivity in spin-orbit coupled 2DEG: Deformation potential and piezoelectric scattering

We study the interaction between electron and acoustic phonon in a Rashba spin-orbit coupled two dimensional electron gas using Boltzmann transport theory. Both deformation potential and piezoelectric scattering mechanisms are considered in the Bloch-Gruneisen (BG) as well as in the equipartition (EP) regimes. Effect of the Rashba spin-orbit interaction on the temperature dependence of resistivity in the BG and EP regimes has been discussed. We find effective exponent of the temperature dependence of the resistivity in the BG regime decreases due to spin-orbit coupling.

cond-mat.mes-hall↗

Zitterbewegung of electrons in quantum wells and dots in presence of an in-plane magnetic field

We study the effect of an in-plane magnetic field on the zitterbewegung (ZB) of electrons in a semiconductor quantum well (QW) and in a quantum dot (QD) with the Rashba and Dresselhaus spin-orbit interactions. We obtain a general expression of the time-evolution of the position vector and current of the electron in a semiconductor quantum well. The amplitude of the oscillatory motion is directly related to the Berry connection in momentum space. We find that in presence of the magnetic field the ZB in a quantum well does not vanish when the strengths of the Rashba and Dresselhaus spin-orbit interactions are equal. The in-plane magnetic field helps to sustain the ZB in quantum wells even at low value of $k_0 d$ (where $d$ is the width of the Gaussian wavepacket and $k_0$ is the initial wave vector). The trembling motion of an electron in a semiconductor quantum well with high Lande g-factor (e.g. InSb) sustains over a long time, even at low value of $k_0 d$. Further, we study the ZB of an electron in quantum dots within the two sub-band model numerically. The trembling motion persists in time even when the magnetic field is absent as well as when the strengths of the SOI are equal. The ZB in quantum dots is due to the superposition of oscillatory motions corresponding to all possible differences of the energy eigenvalues of the system. This is an another example of multi-frequency ZB phenomenon.

cond-mat.mes-hall↗

Quantum information entropies of ultra-cold atomic gases in a harmonic trap

The position and momentum space information entropies of weakly interacting trapped atomic Bose-Einstein condensates and spin-polarized trapped atomic Fermi gases at absolute zero temperature are evaluated. We find that sum of the position and momentum space information entropies of these quantum systems contain $N$ atoms confined in a $D(\le 3)$-dimensional harmonic trap has a universal form as $ S_t^{(D)} = N(a D - b \ln N) $, where $a \simeq 2.332$ and $b = 2$ for interacting bosonic systems and $a \simeq 1.982$ and $b = 1$ for ideal fermionic systems. These results obey the entropic uncertainty relation given by the Beckner, Bialynicki-Birula and Myceilski.

cond-mat.quant-gas↗