The transversal conductivity of the gap-modification of the graphene was studied in the cases of weak nonquatizing and quantizing magnetic field. In the case of nonquantizing magnetic field the expression of the curre...The transversal conductivity of the gap-modification of the graphene was studied in the cases of weak nonquatizing and quantizing magnetic field. In the case of nonquantizing magnetic field the expression of the current density was derived from the Boltzmann equation. The dependence of conductivity and Hall conductivity on the magnetic field intensity was investigated. In the case of quantizing magnetic field the expression for the graphene transversal magnetoconductivity taking into account the scattering on the acoustic phonons was derived in the Born approximation. The graphene conductivity dependence on the magnetic field intensity was investigated. The graphene conductivity was shown to have the oscillations when the magnetic field intensity changes. The features of the Shubnikov-de Haas oscillations in graphene superlattice are discussed.展开更多
A gated Hall-bar device is made from an epitaxially grown,free-standing InSb nanosheet on a hexagonal boron nitride(hBN)dielectric/graphite gate structure and the electron transport properties in the InSb nanosheet ar...A gated Hall-bar device is made from an epitaxially grown,free-standing InSb nanosheet on a hexagonal boron nitride(hBN)dielectric/graphite gate structure and the electron transport properties in the InSb nanosheet are studied by gate-transfer characteristic and magnetotransport measurements at low temperatures.The measurements show that the carriers in the InSb nanosheet are of electrons and the carrier density in the nanosheet can be highly efficiently tuned by the graphite gate.The mobility of the electrons in the InSb nanosheet is extracted from low-field magneotransport measurements and a value of the mobility exceeding~1.8×10^(4) cm^(2)·V^(-1)·s^(-1) is found.High-field magentotransport measurements show well-defined Shubnikov-de Haas(SdH)oscillations in the longitudinal resistance of the InSb nanosheet.Temperature-dependent measurements of the SdH oscillations are carried out and key transport parameters,including the electron effective mass m*~0.028m0 and the quantum lifetimeτ~0.046 ps,in the InSb nanosheet are extracted.It is for the first time that such experimental measurements have been reported for a free-standing InSb nanosheet and the results obtained indicate that InSb nanosheet/hBN/graphite gate structures can be used to develop advanced quantum devices for novel physics studies and for quantum technology applications.展开更多
文摘The transversal conductivity of the gap-modification of the graphene was studied in the cases of weak nonquatizing and quantizing magnetic field. In the case of nonquantizing magnetic field the expression of the current density was derived from the Boltzmann equation. The dependence of conductivity and Hall conductivity on the magnetic field intensity was investigated. In the case of quantizing magnetic field the expression for the graphene transversal magnetoconductivity taking into account the scattering on the acoustic phonons was derived in the Born approximation. The graphene conductivity dependence on the magnetic field intensity was investigated. The graphene conductivity was shown to have the oscillations when the magnetic field intensity changes. The features of the Shubnikov-de Haas oscillations in graphene superlattice are discussed.
基金Project supported by National Key Research and Development Program of China(Grant Nos.2017YFA0303304 and 2016YFA0300601)the National Natural Science Foundation of China(Grant Nos.92165208,92065106,61974138,11874071,91221202,and 91421303)+1 种基金the Beijing Academy of Quantum Information Sciences(Grant No.Y18G22)Dong Pan also acknowledges the support from the Youth Innovation Promotion Association,Chinese Academy of Sciences(Grant Nos.2017156 and Y2021043).
文摘A gated Hall-bar device is made from an epitaxially grown,free-standing InSb nanosheet on a hexagonal boron nitride(hBN)dielectric/graphite gate structure and the electron transport properties in the InSb nanosheet are studied by gate-transfer characteristic and magnetotransport measurements at low temperatures.The measurements show that the carriers in the InSb nanosheet are of electrons and the carrier density in the nanosheet can be highly efficiently tuned by the graphite gate.The mobility of the electrons in the InSb nanosheet is extracted from low-field magneotransport measurements and a value of the mobility exceeding~1.8×10^(4) cm^(2)·V^(-1)·s^(-1) is found.High-field magentotransport measurements show well-defined Shubnikov-de Haas(SdH)oscillations in the longitudinal resistance of the InSb nanosheet.Temperature-dependent measurements of the SdH oscillations are carried out and key transport parameters,including the electron effective mass m*~0.028m0 and the quantum lifetimeτ~0.046 ps,in the InSb nanosheet are extracted.It is for the first time that such experimental measurements have been reported for a free-standing InSb nanosheet and the results obtained indicate that InSb nanosheet/hBN/graphite gate structures can be used to develop advanced quantum devices for novel physics studies and for quantum technology applications.
