1201.5252 (Tutul Biswas et al.)

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

Tutul Biswas, Tarun Kanti Ghosh

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.

View original: http://arxiv.org/abs/1201.5252