Transport Properties of Topological Insulator Bi0.83Sb0.17 Nanowires

2015 ◽  
Vol 1785 ◽  
pp. 1-6
Author(s):  
L.A. Konopko ◽  
A.A. Nikolaeva ◽  
T.E. Huber ◽  
J.P. Ansermet
Keyword(s):  
Magnetic Field ◽  
Single Crystal ◽  
Transport Properties ◽  
Topological Insulator ◽  
Energy Gap ◽  
Oscillation Amplitude ◽  
Glass Capillary ◽  
Wire Axis ◽  
Temperature Dependences ◽  
The Wire

ABSTRACTWe have investigated the transport properties of topological insulator based on single-crystal Bi0.83Sb0.17 nanowires. The single-crystal nanowire samples in the diameter range 200 nm – 1.1 μm were prepared by the high frequency liquid phase casting in a glass capillary using an improved Ulitovsky technique; they were cylindrical single-crystals with (1011) orientation along the wire axis. In this orientation, the wire axis makes an angle of 19.5o with the bisector axis C1 in the bisector-trigonal plane. Bi0.83Sb0.17 is a narrow gap semiconductor with energy gap at L point of Brillouin zone ΔE= 21 meV. In accordance with the measurements of the temperature dependence of the resistivity of the samples resistance increases with decreasing temperature, but at low temperatures decrease in the resistance is observed. This effect, decrease in the resistance, is a clear manifestation of the interesting properties of topological insulators - the presence on its surface of a highly conducting zone. The Arrhenius plot of resistance R in samples with diameter d=1.1 µm and d=200 nm indicates a thermal activation behavior with an activation gap ΔE= 21 and 35 meV, respectively, which proves the presence of the quantum size effect in these samples. We found that in the range of diameter 1100 nm - 200 nm when the diameter decreases the energy gap is growing as 1/d. We have investigated magnetoresistance of Bi0.83Sb0.17 nanowires at various magnetic field orientations. From the temperature dependences of Shubnikov de Haas oscillation amplitude for different orientation of magnetic field we have calculated the cyclotron mass mc and Dingle temperature TD for longitudinal and transverse (B||C3 and B||C2) directions of magnetic fields, which equal 1.96*10-2m0, 9.8 K, 8.5*10-3m0 , 9.4 K and 1.5*10-1m0 , 2.8 K respectively. The observed effects are discussed.

scholarly journals Квантовый размерный эффект и осцилляции Шубникова–де Гааза в поперечном магнитном поле в полупроводниковых нитях Bi0,92Sb0,08

2021 ◽  
Vol 57 (6) ◽  
pp. 79-86
Author(s):  
A.A. Nicolaeva ◽  
◽  
L.A. Conopco ◽  
I.A. Popov ◽  
G.I. Para ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Size Effect ◽  
Topological Insulator ◽  
Energy Gap ◽  
Surface States ◽  
Quantum Size Effect ◽  
Linear Dispersion ◽  
Quantum Size ◽  
Sdh Oscillations ◽  
The Wire

The transport properties, magnetoresistance, and Shubnikov–de Haas (SdH) oscillations of glass-coated Bi0.92Sb0.08 single-crystal wires with diameters of 180 nm to 2.2 mm and the (1011) orientation along the wire axis, which are prepared by liquid phase casting, have been studied. For the first time, it has been found that the energy gap DE increases by a factor of 4 with a decrease in the wire diameter d owing to the manifestation of the quantum size effect. This significant increase in the energy gap can occur under conditions of an energy–momentum linear dispersion relation, which is characteristic of both the gapless state and the surface states of a topological insulator. It has been shown that, in a strong magnetic field at low temperatures, a semiconductor–semimetal transition occurs; it is evident in the temperature dependences of resistance in a magnetic field. An analysis of the SdH oscillations, namely, the phase shift of the Landau levels and the features of the angular dependences of the oscillation periods, suggests that the combination of the manifestation of the topological insulator properties and the quantum size effect leads to the occurrence of new effects in low-dimensional structures, which requires new scientific approaches and applications in microelectronics

Electrical transport properties of FeSe single crystal under high magnetic field

2021 ◽  
Vol 64 (8) ◽  
Author(s):  
HongHui Wang ◽  
ZhaoHui Cheng ◽  
MengZhu Shi ◽  
DongHui Ma ◽  
WeiZhuang Zhuo ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Single Crystal ◽  
Transport Properties ◽  
High Magnetic Field ◽  
Electrical Transport ◽  
Electrical Transport Properties

scholarly journals Single Crystal Growth and Transport Properties of Cu-doped Topological Insulator Bi2Se3

2012 ◽  
Vol 36 ◽  
pp. 638-643 ◽  
Author(s):  
Z.J. Li ◽  
Y. Liu ◽  
S.C. White ◽  
P. Wahl ◽  
X.M. Xie ◽  
...  
Keyword(s):  
Crystal Growth ◽  
Single Crystal ◽  
Transport Properties ◽  
Topological Insulator ◽  
Single Crystal Growth

scholarly journals Nonsaturating large magnetoresistance in semimetals

2018 ◽  
Vol 115 (42) ◽  
pp. 10570-10575 ◽  
Author(s):  
Ian A. Leahy ◽  
Yu-Ping Lin ◽  
Peter E. Siegfried ◽  
Andrew C. Treglia ◽  
Justin C. W. Song ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Susceptibility ◽  
Transport Properties ◽  
Applied Magnetic Field ◽  
Charge Compensation ◽  
Linear Dispersion ◽  
Dominant Mechanism ◽  
Temperature Dependences ◽  
Topological Semimetals ◽  
Different Origins

The rapidly expanding class of quantum materials known as topological semimetals (TSMs) displays unique transport properties, including a striking dependence of resistivity on applied magnetic field, that are of great interest for both scientific and technological reasons. So far, many possible sources of extraordinarily large nonsaturating magnetoresistance have been proposed. However, experimental signatures that can identify or discern the dominant mechanism and connect to available theories are scarce. Here we present the magnetic susceptibility (χ), the tangent of the Hall angle (tan⁡θH), along with magnetoresistance in four different nonmagnetic semimetals with high mobilities, NbP, TaP, NbSb2, and TaSb2, all of which exhibit nonsaturating large magnetoresistance (MR). We find that the distinctly different temperature dependences, χ(T), and the values of tan⁡θH in phosphides and antimonates serve as empirical criteria to sort the MR from different origins: NbP and TaP are uncompensated semimetals with linear dispersion, in which the nonsaturating magnetoresistance arises due to guiding center motion, while NbSb2 and TaSb2 are compensated semimetals, with a magnetoresistance emerging from nearly perfect charge compensation of two quadratic bands. Our results illustrate how a combination of magnetotransport and susceptibility measurements may be used to categorize the increasingly ubiquitous nonsaturating large magnetoresistance in TSMs.

NUMERICAL STUDY OF TRANSPORT PROPERTIES IN TOPOLOGICAL INSULATOR QUANTUM DOTS UNDER MAGNETIC FIELD

2013 ◽  
Vol 27 (14) ◽  
pp. 1350104 ◽  
Author(s):  
SHENG-NAN ZHANG ◽  
HUA JIANG ◽  
HAIWEN LIU
Keyword(s):  
Magnetic Field ◽  
Quantum Dots ◽  
Transport Properties ◽  
Topological Insulator ◽  
Numerical Study ◽  
Spin Polarized ◽  
Full Band ◽  
Spin Degeneracy ◽  
Aharonov Bohm ◽  
The Magnetic Field

In this paper, we investigate the transport properties of HgTe / CdTe -based topological insulator quantum dots (TIQDs) under magnetic field. Both disk and square shaped TIQDs are considered and the magneto-conductance are calculated numerically for various magnetic field strength. The magnetic field lifts the spin degeneracy, leading to spin polarized current at given Fermi energy. Meanwhile, the magneto-conductance demonstrates the Aharonov–Bohm (AB) oscillation with a period of one flux quantum [Formula: see text]. Numerical results for AB oscillation features indicate the mismatch between electron (e) and hole (h) doping conditions, which can be attributed to the e–h asymmetry in the full band Hamiltonian. Further, interference effect emerges around bulk and edge energy degenerate points, subsequently suppressing the magneto-conductance in both shaped systems. All these physical characteristics are qualitatively consistent for disk and square shaped TIQDs due to the topological nature of edge modes.

Angular dependence of giant magneto impedance and magnetic characteristic of Co-based wire in different magnetic field ranges

2014 ◽  
Vol 28 (25) ◽  
pp. 1450197 ◽  
Author(s):  
Reza Mardani ◽  
Ahmad Amirabadizadeh ◽  
Majid Ghanaatshoar
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Angular Dependence ◽  
Hysteresis Loops ◽  
Magnetic Characteristic ◽  
Field Range ◽  
Wire Axis ◽  
Amorphous Wires ◽  
Giant Magneto Impedance ◽  
The Wire

Angular dependence of the giant magneto impedance (GMI), hysteresis loops and magnetization curves have been investigated in amorphous wires with respect to direction and amplitude of the magnetic field in room temperature. The measurements were performed at different orientation angles of the applied magnetic field relative to the wire axis and various magnetic field strengths in moderate (0–200 Oe) and high (0–5000 Oe) ranges. The highest GMI response (500%) and magnetization (100 emu/gr) were found for angles close to the wire axis in high magnetic field range. By increasing the angle from 0°, in moderate external magnetic fields the GMI and magnetization decrease without reaching the saturation. However, in high magnetic fields (~ 5000 Oe) these parameters are nearly constant and almost saturated for all angles. In both magnetic field ranges, increasing the angle of applied field widens the impedance curves.

scholarly journals The Stratified Superconductivity in Ba0.6K0.4BiO3 Single Crystal: Direct Measurement of Energy Gap between Homo-, and Inhomogeneous States

2014 ◽  
Vol 2014 ◽  
pp. 1-9
Author(s):  
L. N. Zherikhina ◽  
A. M. Tskhovrebov ◽  
L. A. Klinkova ◽  
D. A. Balaev ◽  
S. I. Popkov ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Fermi Surface ◽  
Single Crystal ◽  
Superconducting State ◽  
Energy Gap ◽  
Electric Transport ◽  
Josephson Tunneling ◽  
Josephson System ◽  
First Time ◽  
Inhomogeneous Superconductor

The existence of space inhomogeneous superconductor insulator state (SISIS) found out earlier in polycrystalline samples of high- TC system Ba0.6K0.4BiO3 (TC≈30 K) is confirmed on Ba0.6K0.4BiO3 single crystal. At T* (T*<TC,T*≈17 K) the transition from the homogeneous superconducting state into the SISIS occurs. SISIS is characterized by the appearance of two gaps on the Fermi surface, semi- and superconducting, which are modulated in space in antiphase, the electric transport between superconducting regions being carried out due to Josephson tunneling. Thus the whole sample becomes a multiple Josephson system. Nonlinear I-V curves are observed on Ba0.6K0.4BiO3 single crystal at temperatures below T*. Dependence of I-V curves on temperature and magnetic field, typical to a Josephson system, was found out. Besides, a step-like peculiarity at the values of voltage of the order of one and two superconducting gaps shows up. These peculiarities are suppressed by magnetic field much earlier than critical current. The new data firstly correlate with the model of SISIS and secondly permit for the first time to determining directly the energy gap between homogeneous and stratified superconductor states.

Electronic structure and transport properties of graphene/h-BN controlled by boundary potential and magnetic field

2020 ◽  
Vol 34 (16) ◽  
pp. 2050180
Author(s):  
Jian Sun ◽  
Lei Xu ◽  
Jun Zhang
Keyword(s):  
Magnetic Field ◽  
Electronic Structure ◽  
Band Structure ◽  
Transport Properties ◽  
Energy Gap ◽  
Edge State ◽  
Stable Configuration ◽  
Edge States ◽  
Boundary Potential ◽  
Lattice Matched

We study the band structure of the lattice-matched graphene/[Formula: see text]-BN bilayer system in the most stable configuration. An effective way to individually manipulate the edge state by the boundary potentials is proposed. It is shown that the boundary potential can not only shift and deform the edge bands, but also modify the energy gap. We also explore the transport properties of graphene/[Formula: see text]-BN under a magnetic field. The boundary potential can change the distribution of the edge states, resulting in an interesting evolution of the quantized conductance.

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