High-Performance Bi2Te3-Based Topological Insulator Film Magnetic Field Detector

Abstract Topological superconductivity is central to a variety of novel phenomena involving the interplay between topologically ordered phases and broken-symmetry states. The key ingredient is an unconventional order parameter, with an orbital component containing a chiral p x + ip y wave term. Here we present phase-sensitive measurements, based on the quantum interference in nanoscale Josephson junctions, realized by using Bi2Te3 topological insulator. We demonstrate that the induced superconductivity is unconventional and consistent with a sign-changing order parameter, such as a chiral p x + ip y component. The magnetic field pattern of the junctions shows a dip at zero externally applied magnetic field, which is an incontrovertible signature of the simultaneous existence of 0 and π coupling within the junction, inherent to a non trivial order parameter phase. The nano-textured morphology of the Bi2Te3 flakes, and the dramatic role played by thermal strain are the surprising key factors for the display of an unconventional induced order parameter.

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Simulation study of the plasma-brake effect

Annales Geophysicae ◽

10.5194/angeo-32-1207-2014 ◽

2014 ◽

Vol 32 (10) ◽

pp. 1207-1216 ◽

Cited By ~ 12

Author(s):

P. Janhunen

Keyword(s):

Magnetic Field ◽

High Performance ◽

Ionospheric Plasma ◽

Low Earth Orbit ◽

Earth Orbit ◽

Breaking Force ◽

Field Orientation ◽

Particle In Cell ◽

Leo Satellite ◽

The Magnetic Field

Abstract. Plasma brake is a thin, negatively biased tether that has been proposed as an efficient concept for deorbiting satellites and debris objects from low Earth orbit. We simulate the interaction with the ionospheric plasma ram flow with the plasma-brake tether by a high-performance electrostatic particle in cell code to evaluate the thrust. The tether is assumed to be perpendicular to the flow. We perform runs for different tether voltage, magnetic-field orientation and plasma-ion mass. We show that a simple analytical thrust formula reproduces most of the simulation results well. The interaction with the tether and the plasma flow is laminar (i.e. smooth and not turbulent) when the magnetic field is perpendicular to the tether and the flow. If the magnetic field is parallel to the tether, the behaviour is unstable and thrust is reduced by a modest factor. The case in which the magnetic field is aligned with the flow can also be unstable, but does not result in notable thrust reduction. We also correct an error in an earlier reference. According to the simulations, the predicted thrust of the plasma brake is large enough to make the method promising for low-Earth-orbit (LEO) satellite deorbiting. As a numerical example, we estimate that a 5 km long plasma-brake tether weighing 0.055 kg could produce 0.43 mN breaking force, which is enough to reduce the orbital altitude of a 260 kg object mass by 100 km over 1 year.

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Experimental Observation of Temperature-Driven Topological Phase Transition in HgTe/CdHgTe Quantum Wells

10.20944/preprints201901.0295.v1 ◽

2019 ◽

Author(s):

Maksim Zholudev ◽

Aleksandr Kadykov ◽

Mikhail Fadeev ◽

Michal Marcinkiewicz ◽

Sandra Ruffenach ◽

...

Keyword(s):

Magnetic Field ◽

Phase Transition ◽

Quantum Wells ◽

Topological Insulator ◽

Critical Magnetic Field ◽

Topological Phase ◽

Temperature Dependent ◽

Transition Parameter ◽

Topological Phase Transition ◽

Band Insulator

We report on comparison between temperature-dependent magneto¬absorption and magnetotransport spectroscopy of HgTe/CdHgTe quantum wells in terms of detection of phase transition between topological insulator and band insulator states. Our results demonstrate that temperature-dependent magnetospectroscopy is a powerful tool to discriminate trivial and topological insulator phases, yet magnetotransport method is shown to have advantages for clear manifestation of the phase transition with accurate quantitative values of transition parameter (i.e. critical magnetic field Bc).

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