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 Monday February 4<br />
Poster 19:<br />
Quantized conductance in InSb nanowires and electrical characterization of<br />
branched InSb nanowires<br />
Ilse van Weperen<br />
Indium antimonide (InSb) nanowires have shown potential for creation of<br />
topological superconducting and helical liquid states. We report on transport<br />
measurements of single high-mobility indium antimonide nanowires and<br />
branched InSb nanowires.<br />
A novel growth mechanism allows two InSb nanowires to merge into a nano-<br />
T or nanocross. Transport measurements of branched nanowires show characteristics<br />
similar to that of single nanowires. Magnetoresistance measurements<br />
of nanocrosses allow extraction of nanowire electron density.<br />
A mean free path of ∼ 300 nm in InSb nanowires enables observation of<br />
one-dimensional conductance channels at high (B > 2 T) magnetic fields.<br />
Conductance quantization is studied as a function of magnetic field and bias<br />
voltage, enabling extraction of an effective g-factor of ∼ 65 and a subband<br />
spacing of ∼ 15 meV.<br />
Poster 20:<br />
Phase-Coherent Transport and Spin-Orbit Coupling in InAs Nanowires<br />
Sebastian Heedt<br />
We report on phase-coherent transport measurements on differently doped<br />
InAs nanowires grown by selective area metalorganic vapor phase epitaxy.<br />
The nanowires are contacted individually and the low-temperature electronic<br />
transport properties are investigated for temperatures down to 30 mK and<br />
magnetic fields up to 10 T. To this end, top-gates with high-k dielectrics are<br />
prepared. At small current-bias the transport is phase-coherent and gives<br />
us the opportunity to determine the phase-coherence length and the spin<br />
relaxation length. The band profile and the carrier concentration of the<br />
nanowires can be manipulated by the application of a gate voltage. An analytical<br />
model for the low-field quantum conductivity correction is utilized<br />
to quantify Rashba and Dresselhaus spin-orbit coupling effects. Nanowires<br />
with different doping concentrations are investigated to gain information<br />
on how the doping of the highly spin-orbit coupled InAs nanowires impacts<br />
the spin-lifetime.<br />
70