94 research outputs found
Magnetoconductance signatures of chiral domain-wall bound states in magnetic topological insulators
Recent magnetoconductance measurements performed on magnetic topological
insulator candidates have revealed butterfly-shaped hysteresis. This hysteresis
has been attributed to the formation of gapless chiral domain-wall bound states
during a magnetic field sweep. We treat this phenomenon theoretically,
providing a link between microscopic magnetization dynamics and butterfly
hysteresis in magnetoconductance. Further, we illustrate how a spatially
resolved conductance measurement can probe the most striking feature of the
domain-wall bound states: their chirality. This work establishes a regime where
a definitive link between butterfly hysteresis in longitudinal
magneto-conductance and domain-wall bound states can be made. This analysis
provides an important tool for the identification of magnetic topological
insulators.Comment: v2: Final published version; 7 pages, 3 figure
Stationary and transient leakage current in the Pauli spin blockade
We study the effects of cotunneling and a non-uniform Zeeman splitting on the
stationary and transient leakage current through a double quantum dot in the
Pauli spin blockade regime. We find that the stationary current due to
cotunneling vanishes at low temperature and large applied magnetic field,
allowing for the dynamical preparation of a pure spin ground state, even at
large voltage bias. Additionally, we analyze current that flows between
blocking events, characterized, in general, by a fractional effective charge
. This charge can be used as a sensitive probe of spin relaxation
mechanisms and can be used to determine the visibility of Rabi oscillations.Comment: v1: 4 pages; v2: 4 pages+ additional supplementary material, version
to appear in PR
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