The Experts below are selected from a list of 252 Experts worldwide ranked by ideXlab platform
Xincheng Xie - One of the best experts on this subject based on the ideXlab platform.
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The level-shifting induced Negative Magnetoresistance in the nearest-neighbor hopping conduction
Europhysics Letters (EPL), 1999Co-Authors: Xiangrong Wang, Xincheng XieAbstract:We propose a new mechanism of Negative Magnetoresistance in non-magnetic granular materials in which electron transport is dominated by hopping between two nearest-neighbor clusters. We study the dependence of Magnetoresistance on temperature and separation between neighboring clusters. At a small separation we find a Negative Magnetoresistance at low temperatures and it changes over to a positive value as temperature increases. For a fixed temperature, Magnetoresistance changes from Negative to positive when the cluster separation increases. The change of Magnetoresistance ΔR/R can be more than 80 % at low temperatures.
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Negative Magnetoresistance in the nearest-neighbor hopping conduction
Europhysics Letters (EPL), 1997Co-Authors: Xiangrong Wang, Xincheng XieAbstract:We propose a size effect which leads to the Negative Magnetoresistance in granular metal-insulator materials in which the hopping between two nearest-neighbor clusters is the main transport mechanism. We show that the hopping probability increases with magnetic field. This is originated from the level crossing in a few-electron cluster. Thus, the overlap of electronic states of two neighboring clusters increases, and Negative Magnetoresistance results.
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Negative Magnetoresistance in the Nearest-neighbor Hopping Conduction
arXiv: Condensed Matter, 1997Co-Authors: Xiangrong Wang, Xincheng XieAbstract:We propose a size effect which leads to the Negative Magnetoresistance in granular metal-insulator materials in which the hopping between two nearest neighbor clusters is the main transport mechanism. We show that the hopping probability increases with magnetic field. This is originated from the level crossing in a few-electron cluster. Thus, the overlap of electronic states of two neighboring clusters increases, and the Negative Magnetoresistance is resulted.
Rizwan Ur Rehman Sagar - One of the best experts on this subject based on the ideXlab platform.
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Nonsaturating Negative Magnetoresistance in laser-induced graphene
Materials Letters, 2019Co-Authors: Rizwan Ur Rehman Sagar, Lunchao Zhong, Yixin Liu, Dandan Hui, Min ZhangAbstract:Abstract Herein, nonsaturating Negative Magnetoresistance (NMR) in laser-induced graphene (LIG) is observed at all temperatures (300–10 K) for the first time to the best of our knowledge. Three-dimensional (3D) variable range hopping conduction is a dominant conduction mechanism in the as-grown and, 350 °C and 400 °C annealed specimens. Flexible and wearable magnetoelectronic devices are possible as LIG is fabricated on polyimide.
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Negative Magnetoresistance in undoped semiconducting amorphous carbon films
Journal of Applied Physics, 2014Co-Authors: Rizwan Ur Rehman Sagar, Xiaozhong Zhang, Jimin Wang, Chengyue XiongAbstract:Amorphous carbon (a-C) films were fabricated by chemical vapor deposition on SiO2 substrate. The a-C films have nano-crystalline sp2 structure with the grain size of ∼5 nm and an optical band gap of ∼1.8 eV. The a-C films show Negative Magnetoresistance (MR) from 300 to 2 K and an anomalous shape change of MR-magnetic field curves at 10 K. Grain boundary scattering theory and weak localization theory were used to explain the MR mechanism and shape change of MR-magnetic field curves.
Xiangrong Wang - One of the best experts on this subject based on the ideXlab platform.
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The level-shifting induced Negative Magnetoresistance in the nearest-neighbor hopping conduction
Europhysics Letters (EPL), 1999Co-Authors: Xiangrong Wang, Xincheng XieAbstract:We propose a new mechanism of Negative Magnetoresistance in non-magnetic granular materials in which electron transport is dominated by hopping between two nearest-neighbor clusters. We study the dependence of Magnetoresistance on temperature and separation between neighboring clusters. At a small separation we find a Negative Magnetoresistance at low temperatures and it changes over to a positive value as temperature increases. For a fixed temperature, Magnetoresistance changes from Negative to positive when the cluster separation increases. The change of Magnetoresistance ΔR/R can be more than 80 % at low temperatures.
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Negative Magnetoresistance in the nearest-neighbor hopping conduction
Europhysics Letters (EPL), 1997Co-Authors: Xiangrong Wang, Xincheng XieAbstract:We propose a size effect which leads to the Negative Magnetoresistance in granular metal-insulator materials in which the hopping between two nearest-neighbor clusters is the main transport mechanism. We show that the hopping probability increases with magnetic field. This is originated from the level crossing in a few-electron cluster. Thus, the overlap of electronic states of two neighboring clusters increases, and Negative Magnetoresistance results.
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Negative Magnetoresistance in the Nearest-neighbor Hopping Conduction
arXiv: Condensed Matter, 1997Co-Authors: Xiangrong Wang, Xincheng XieAbstract:We propose a size effect which leads to the Negative Magnetoresistance in granular metal-insulator materials in which the hopping between two nearest neighbor clusters is the main transport mechanism. We show that the hopping probability increases with magnetic field. This is originated from the level crossing in a few-electron cluster. Thus, the overlap of electronic states of two neighboring clusters increases, and the Negative Magnetoresistance is resulted.
Gerard Biskupski - One of the best experts on this subject based on the ideXlab platform.
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Variable range hopping conductivity and Negative Magnetoresistance in n-type InP semiconductor
Solid-State Electronics, 2009Co-Authors: R. Abdia, A. El Kaaouachi, A. Nafidi, Gerard Biskupski, J. HemineAbstract:Abstract The low temperature electrical conductivity behaviour of the n-type InP sample in the insulating regime of the metal–insulator transition is studied in magnetic fields. A Negative Magnetoresistance is observed and follows the variable range hopping mechanism of conduction. The Negative Magnetoresistance Δ ρ / ρ 0 varies as f 1 ( T ) B 2 in low magnetic fields and as f 2 ( T ) B in moderate fields both in agreement with the theoretical predictions based on quantum interference. The resistance follows the Efros–Shklovskii variable range hopping as ln ραT − 1/2 in the presence of a Coulomb gap in the density of states.
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Positive and Negative Magnetoresistance in the variable-range-hopping regime of doped semiconductors
Philosophical Magazine B, 1992Co-Authors: Gerard BiskupskiAbstract:Abstract Experimental results are reported on high-field positive and Negative Magnetoresistance in semiconducting materials in which variable-range hopping occurs at low temperatures. In the case of positive Magnetoresistance, both the Mott (T −1/4) and the Shklovskii-Efros (T −1/2) regimes, are observed. We discuss the transition between these two regimes, the shape of the Coulomb gap, and the scaling behaviour of the parameter T o. At low magnetic fields and for different semiconducting materials, we have observed a Negative Magnetoresistance associated with variable-range-hopping conduction. Experimental data are tentatively compared with available models for orbital Magnetoresistance mechanisms, based on quantum interference between tunnelling paths in the insulating regime.
Yoshimasa Hidaka - One of the best experts on this subject based on the ideXlab platform.
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Resummation for the Field-theoretical Derivation of the Negative Magnetoresistance
Journal of High Energy Physics, 2020Co-Authors: Kenji Fukushima, Yoshimasa HidakaAbstract:We show detailed derivation of the electric conductivity of quark matter at finite temperature and density under a magnetic field. We especially focus on the longitudinal electric conductivity along the magnetic direction and establish the field-theoretical description of the Negative Magnetoresistance as observed in chiral materials. With increasing magnetic field our microscopic calculation leads to changing behavior from approximately quadratic to asymptotically linear dependence of the electric conductivity, while the magnetic dependence is quadratic in the conventional relaxation time approximation. The presented formulation founds a firm basis for the physical interpretation of the Negative Magnetoresistance as manifestation of the chiral anomaly, as well as it offers general methodology applicable for various transport coefficients.
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resummation for the field theoretical derivation of the Negative Magnetoresistance
Journal of High Energy Physics, 2020Co-Authors: Kenji Fukushima, Yoshimasa HidakaAbstract:We show detailed derivation of the electric conductivity of quark matter at finite temperature and density under a magnetic field. We especially focus on the longitudinal electric conductivity along the magnetic direction and establish the field-theoretical description of the Negative Magnetoresistance as observed in chiral materials. With increasing magnetic field our microscopic calculation leads to changing behavior from approximately quadratic to asymptotically linear dependence of the electric conductivity, while the magnetic dependence is quadratic in the conventional relaxation time approximation. The presented formulation founds a firm basis for the physical interpretation of the Negative Magnetoresistance in terms of the particle and the hydrodynamic contributions, as well as it offers general methodology applicable for various transport coefficients.
