A theoretical study of resonant tunneling is carried out for an inverse parabolic double-barrier structure subjected to an external electric field. Tunneling transmission coefficient and density of states are analyzed...A theoretical study of resonant tunneling is carried out for an inverse parabolic double-barrier structure subjected to an external electric field. Tunneling transmission coefficient and density of states are analyzed by using the non-equilibrium Green＇s function approach based on the finite difference method. It is found that the resonant peak of the transmission coefficient, being unity for a symmetrical case, reduces under the applied electric field and depends strongly on the variation of the structure parameters.展开更多
A solid-state thermoelectric refrigerator with a cylindrical InP/InAs/InP double-barrier heterostructure is proposed. Based on the ballistic electron transport and the asymmetrical transmission, we derive the expressi...A solid-state thermoelectric refrigerator with a cylindrical InP/InAs/InP double-barrier heterostructure is proposed. Based on the ballistic electron transport and the asymmetrical transmission, we derive the expressions of the performance parameters of this refrigerator. The cooling rate rather than the coefficient of performance is affected by the area of the inner cylinder. Then through the numerical simulation, a triangular cooling rate region is found with respect to the chemical potential and bias voltage; further, that it is because of the small full width at half maximum of the transmission resonance and the linear relationship between the energy position of resonance and the bias voltage. These tunable results might supply some guide to the cooling in tiny components or devices.展开更多
The graphene-based double-barrier waveguides induced by electric field have been investigated. The guided modes can only exist in the case of Klein tunneling, and the fundamental mode is absent. The guided modes in th...The graphene-based double-barrier waveguides induced by electric field have been investigated. The guided modes can only exist in the case of Klein tunneling, and the fundamental mode is absent. The guided modes in the single-barrier waveguide split into symmetric and antisymmetric modes with different incident angles in the double-barrier waveguide. The phase difference between electron states and hole states is also discussed. The phase difference for the two splitting modes is close to each other and increases with the order of guided modes. These phenomena can be helpful for the potential applications in graphene-based optoelectronic devices.展开更多
The transport property of electron through graphene-based double-barrier under a time periodic field is investigated. We study the influence of the system parameters and external field strength on the transmission pro...The transport property of electron through graphene-based double-barrier under a time periodic field is investigated. We study the influence of the system parameters and external field strength on the transmission probability. The results show that transmission exhibits various kinds of behavior with the change of parameters due to its angular anisotropy. One could control the values of transmission and conductivity as well as their distribution in each band by tuning the parameters.展开更多
We present an analytical solution of two solitons of Bose-Einstein condensates trapped in a double-barrier potential by using a multiple-scale method. In the linear case, we find that the stable spots of the soliton f...We present an analytical solution of two solitons of Bose-Einstein condensates trapped in a double-barrier potential by using a multiple-scale method. In the linear case, we find that the stable spots of the soliton formation are at the top of the barrier potential and at the region of barrier potential absence. For weak nonlinearity, it is shown that the height of the barrier potential has an important effect on the dark soliton dynamical properties. Especially, in the case of regarding a double-barrier potential as the output source of the solitons, the collision spots between two dark solitons can be controlled by the height of the barrier potential.展开更多
Fabricated are the double-barrier light emission tunnel junctions successfully. Introduced are the fabrication process and light emission characteristics. The spectra of the junctions are measured and analyzed especia...Fabricated are the double-barrier light emission tunnel junctions successfully. Introduced are the fabrication process and light emission characteristics. The spectra of the junctions are measured and analyzed especially. Their spectrum wavelength including main wave peak(locates at 450 nm^500 nm) of the double-barrier junction shows a "blue shift" in comparison with that of the single-barrier Metal/Insulator/Semiconductor(MIS) or Metal/Insulator/Metal(MIM) junction(wave peak locates at 620 nm^740 nm). This phenomenon should be due to the occurrence of the electron resonant tunneling in the double-barrier junction.展开更多
GaN power electronic devices,such as the lateral AlGaN/GaN Schottky barrier diode(SBD),have received significant attention in recent years.Many studies have focused on optimizing the breakdown voltage(BV)of the device...GaN power electronic devices,such as the lateral AlGaN/GaN Schottky barrier diode(SBD),have received significant attention in recent years.Many studies have focused on optimizing the breakdown voltage(BV)of the device,with a particular emphasis on achieving ultra-high-voltage(UHV,>10 kV)applications.However,another important question arises:can the device maintain a BV of 10 kV while having a low turn-on voltage(V_(on))?In this study,the fabrication of UHV AlGaN/GaN SBDs was demonstrated on sapphire with a BV exceeding 10 kV.Moreover,by utilizing a doublebarrier anode(DBA)structure consisting of platinum(Pt)and tantalum(Ta),a remarkably low Von of 0.36 V was achieved.This achievement highlights the great potential of these devices for UHV applications.展开更多
The fabrication process of Cu/Al2O3/MgF2/Au double-barrier metal/insulator/metal junction （DMIMJ） was introduced, and more stable light emission from this junction was successfully observed. The light emission physi...The fabrication process of Cu/Al2O3/MgF2/Au double-barrier metal/insulator/metal junction （DMIMJ） was introduced, and more stable light emission from this junction was successfully observed. The light emission physical mechanism of the junction was discussed. Results show that light emission spectrum of this structure locates at wavelength of 250-700 nm with two peaks at around 460 nm and 640 nm, which moves towards shorter wavelength region in comparison with that of the Al/Al2O3/Au junction. The light emission efficiency of this junction ranges from 0.7×10^-5-2.0×10^-5, which is 1 to 2 orders higher than that of the single-barrier Al/Al2O3/Au junction. The improved properties of this structure should be due to the electrons resonant tunneling effect in the double-barrier.展开更多
This paper investigates the effect of Dresselhaus spin orbit coupling on the spin-transport properties of ferromagnet/insulator/semiconductor/insulator/ferromagnet double-barrier structures. The influence of the thick...This paper investigates the effect of Dresselhaus spin orbit coupling on the spin-transport properties of ferromagnet/insulator/semiconductor/insulator/ferromagnet double-barrier structures. The influence of the thickness of the insulator between the ferromagnet and the semiconductor on the polarization is also considered. The obtained results indicate that （i） the polarization can be enhanced by reducing the insulator layers at zero temperature, and （ii） the tunnelling magnetoresistance inversion can be illustrated by the influence of the Dresselhaus spin-orbit coupling effect in the double-barrier structure. Due to the Dresselhaus spin-orbit coupling effect, the tunnelling magnetoresistance inversion occurs when the energy of a localized state in the barrier matches the Fermi energy EF of the ferromagnetic electrodes.展开更多
We study the electron transport through the double-barrier junction consmte^l o~ tne pn^nalocyamn~ molecule adsorbed on a NaCl bilayer on a metal substrate and the STM tip from first principles. The hydrogen tautomeri...We study the electron transport through the double-barrier junction consmte^l o~ tne pn^nalocyamn~ molecule adsorbed on a NaCl bilayer on a metal substrate and the STM tip from first principles. The hydrogen tautomerization reaction happened in the molecule changes the spatial extensions of the molecular 7c orbitals under the tip, leading to junction conductance switching. Shifting the molecule to locate on different ions also varies the conductance. Tile transport channels of the tautomers on different adsorbed sites are identified.展开更多
文摘A theoretical study of resonant tunneling is carried out for an inverse parabolic double-barrier structure subjected to an external electric field. Tunneling transmission coefficient and density of states are analyzed by using the non-equilibrium Green＇s function approach based on the finite difference method. It is found that the resonant peak of the transmission coefficient, being unity for a symmetrical case, reduces under the applied electric field and depends strongly on the variation of the structure parameters.
基金Project supported by the Fundamental Research Funds for the Central Universities and the Research and Innovation Project for College Graduates of Jiangsu Province,China(Grant No.CXZZ13 0081)
文摘A solid-state thermoelectric refrigerator with a cylindrical InP/InAs/InP double-barrier heterostructure is proposed. Based on the ballistic electron transport and the asymmetrical transmission, we derive the expressions of the performance parameters of this refrigerator. The cooling rate rather than the coefficient of performance is affected by the area of the inner cylinder. Then through the numerical simulation, a triangular cooling rate region is found with respect to the chemical potential and bias voltage; further, that it is because of the small full width at half maximum of the transmission resonance and the linear relationship between the energy position of resonance and the bias voltage. These tunable results might supply some guide to the cooling in tiny components or devices.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11204170 and 61108010)the Shanghai Municipal Commission of Science and Technology,China(Grant No.16ZR1411600)
文摘The graphene-based double-barrier waveguides induced by electric field have been investigated. The guided modes can only exist in the case of Klein tunneling, and the fundamental mode is absent. The guided modes in the single-barrier waveguide split into symmetric and antisymmetric modes with different incident angles in the double-barrier waveguide. The phase difference between electron states and hole states is also discussed. The phase difference for the two splitting modes is close to each other and increases with the order of guided modes. These phenomena can be helpful for the potential applications in graphene-based optoelectronic devices.
基金Supported in part by the National Natural Science Foundation of China under Grant Nos. 10775100, 10974137, 11047172, 11047020, and 11047173by the Fund of Nuclear Theory Center of HIRFL of China
文摘The transport property of electron through graphene-based double-barrier under a time periodic field is investigated. We study the influence of the system parameters and external field strength on the transmission probability. The results show that transmission exhibits various kinds of behavior with the change of parameters due to its angular anisotropy. One could control the values of transmission and conductivity as well as their distribution in each band by tuning the parameters.
基金Project supported by the Science Research Foundation of the Education Bureau of Hunan Province of China (Grant No.09C227)
文摘We present an analytical solution of two solitons of Bose-Einstein condensates trapped in a double-barrier potential by using a multiple-scale method. In the linear case, we find that the stable spots of the soliton formation are at the top of the barrier potential and at the region of barrier potential absence. For weak nonlinearity, it is shown that the height of the barrier potential has an important effect on the dark soliton dynamical properties. Especially, in the case of regarding a double-barrier potential as the output source of the solitons, the collision spots between two dark solitons can be controlled by the height of the barrier potential.
基金National Natural Science Foundation of China(69576006)
文摘Fabricated are the double-barrier light emission tunnel junctions successfully. Introduced are the fabrication process and light emission characteristics. The spectra of the junctions are measured and analyzed especially. Their spectrum wavelength including main wave peak(locates at 450 nm^500 nm) of the double-barrier junction shows a "blue shift" in comparison with that of the single-barrier Metal/Insulator/Semiconductor(MIS) or Metal/Insulator/Metal(MIM) junction(wave peak locates at 620 nm^740 nm). This phenomenon should be due to the occurrence of the electron resonant tunneling in the double-barrier junction.
基金supported by National Key R&D Project grant No.2022YFE0122700)National High-Tech R&D Project(grant No.2015AA033305)+2 种基金Jiangsu Provincial Key R&D Program(grant No.BK2015111)China Postdoctoral Science Foundation(grant No.2023M731583)Jiangsu Provincial Innovation and Entrepreneurship Doctor Program,the Research and Development Funds from State Grid Shandong Electric Power Company and Electric Power Research Institute.
文摘GaN power electronic devices,such as the lateral AlGaN/GaN Schottky barrier diode(SBD),have received significant attention in recent years.Many studies have focused on optimizing the breakdown voltage(BV)of the device,with a particular emphasis on achieving ultra-high-voltage(UHV,>10 kV)applications.However,another important question arises:can the device maintain a BV of 10 kV while having a low turn-on voltage(V_(on))?In this study,the fabrication of UHV AlGaN/GaN SBDs was demonstrated on sapphire with a BV exceeding 10 kV.Moreover,by utilizing a doublebarrier anode(DBA)structure consisting of platinum(Pt)and tantalum(Ta),a remarkably low Von of 0.36 V was achieved.This achievement highlights the great potential of these devices for UHV applications.
基金Funded by the National Natural Science Foundation of China (No.69576006)
文摘The fabrication process of Cu/Al2O3/MgF2/Au double-barrier metal/insulator/metal junction （DMIMJ） was introduced, and more stable light emission from this junction was successfully observed. The light emission physical mechanism of the junction was discussed. Results show that light emission spectrum of this structure locates at wavelength of 250-700 nm with two peaks at around 460 nm and 640 nm, which moves towards shorter wavelength region in comparison with that of the Al/Al2O3/Au junction. The light emission efficiency of this junction ranges from 0.7×10^-5-2.0×10^-5, which is 1 to 2 orders higher than that of the single-barrier Al/Al2O3/Au junction. The improved properties of this structure should be due to the electrons resonant tunneling effect in the double-barrier.
基金supported by the National Natural Science Foundation of China (Grant No 10674040)the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No 20060094002)
文摘This paper investigates the effect of Dresselhaus spin orbit coupling on the spin-transport properties of ferromagnet/insulator/semiconductor/insulator/ferromagnet double-barrier structures. The influence of the thickness of the insulator between the ferromagnet and the semiconductor on the polarization is also considered. The obtained results indicate that （i） the polarization can be enhanced by reducing the insulator layers at zero temperature, and （ii） the tunnelling magnetoresistance inversion can be illustrated by the influence of the Dresselhaus spin-orbit coupling effect in the double-barrier structure. Due to the Dresselhaus spin-orbit coupling effect, the tunnelling magnetoresistance inversion occurs when the energy of a localized state in the barrier matches the Fermi energy EF of the ferromagnetic electrodes.
文摘We study the electron transport through the double-barrier junction consmte^l o~ tne pn^nalocyamn~ molecule adsorbed on a NaCl bilayer on a metal substrate and the STM tip from first principles. The hydrogen tautomerization reaction happened in the molecule changes the spatial extensions of the molecular 7c orbitals under the tip, leading to junction conductance switching. Shifting the molecule to locate on different ions also varies the conductance. Tile transport channels of the tautomers on different adsorbed sites are identified.
