Workshop book - Physikzentrum der RWTH Aachen - RWTH Aachen ...
Workshop book - Physikzentrum der RWTH Aachen - RWTH Aachen ...
Workshop book - Physikzentrum der RWTH Aachen - RWTH Aachen ...
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Posters Tuesday February 5<br />
Poster 32:<br />
Intrinsic and substrate induced spin-orbit interaction in chirally stacked trilayer<br />
graphene<br />
Andor Kormanyos<br />
We present a combined group-theoretical and tight-binding approach to<br />
calculate the intrinsic spin-orbit coupling (SOC) in ABC stacked trilayer<br />
graphene. As a special case of our calculations we also consi<strong>der</strong> the intrinsic<br />
SOC in bilayer graphene. The comparison between our tight-binding bilayer<br />
results and the density functional computations of Konschuh et. al. allows<br />
us to estimate the values of the trilayer SOC parameters as well. We also<br />
discuss the situation when a substrate or adatoms induce strong SOC in<br />
only one of the layers of bilayer or ABC trilayer graphene. Both for the<br />
case of intrinsic and externally induced SOC we <strong>der</strong>ive effective Hamiltonians<br />
which describe the low-energy spin-orbit physics. We find that at the K point<br />
of the Brillouin zone the effect of Bychkov-Rashba type SOC is suppressed<br />
in bilayer and ABC trilayer graphene compared to monolayer graphene.<br />
Poster 33:<br />
Spin-orbit induced strong coupling of a single spin to a nanomechanical resonator<br />
Andras Palyi<br />
We theoretically investigate the spin-orbit-induced coupling of an electron<br />
spin to a bending vibrational mode in suspended carbon nanotube quantum<br />
dots. Our estimates indicate that, with current capabilities, a quantum dot<br />
with an odd number of electrons can serve as a realization of the Jaynes-<br />
Cummings model of quantum electrodynamics in the strong-coupling regime.<br />
A bending mode of the suspended tube plays the role of the optical mode and<br />
we identify two distinct two-level subspaces, at small and large magnetic field,<br />
which can be used as qubits in this setup. The strong intrinsic spin-mechanical<br />
coupling allows for detection, as well as manipulation of the spin qubit,<br />
and may yield enhanced performance of nanotubes in sensing applications.<br />
Reference:<br />
A. Palyi, P. R. Struck, M. Rudner, K. Flensberg and G. Burkard, Phys.<br />
Rev. Lett. 108, 206811 (2012)<br />
79