The transfer matrices for both nonsingular and singular cases are constructed to ensure efficient and accurate numerical computation on the electronic and transport properties of graphene quantum wells and superlattic...The transfer matrices for both nonsingular and singular cases are constructed to ensure efficient and accurate numerical computation on the electronic and transport properties of graphene quantum wells and superlattices driven by periodic linear potential.An intuitive interpretation is given for the evolution behavior of the current flowing through the multiple graphene quantum wells/barriers by analyzing the interrelationship among the transmission,bias voltage,incident velocity,and linear potential ranges.The energy minibands and density of states of the graphene superlattices with different periods are also examined by using analytical and numerical methods,showing that the period of superlattices plays a crucial role in energy bands and density of states.展开更多
The single-electron tunneling processes in optically excited coupled quantum dots can be divided into two parts:the electron and the hole parts,which are analytically obtained in the framework of the Keldysh formalism...The single-electron tunneling processes in optically excited coupled quantum dots can be divided into two parts:the electron and the hole parts,which are analytically obtained in the framework of the Keldysh formalism.The tunneling process is selective tunneling,which results in dark tunneling states.The tunneling currents are co-determined by the resonance energies and probability distributions of the particular quantum channels defined by the electron-hole complex resonant states.展开更多
Based on a two-band tight-binding model,the dynamics of electrons under the action of static electric fields with Markoffian dephasing is investigated.The effective scattering time is obtained under the conditions of ...Based on a two-band tight-binding model,the dynamics of electrons under the action of static electric fields with Markoffian dephasing is investigated.The effective scattering time is obtained under the conditions of long-time limit and small interband communication through a perturbative calculation,from which the signature of Zener resonances and relatively long time evolution behavior are predicted.展开更多
文摘The transfer matrices for both nonsingular and singular cases are constructed to ensure efficient and accurate numerical computation on the electronic and transport properties of graphene quantum wells and superlattices driven by periodic linear potential.An intuitive interpretation is given for the evolution behavior of the current flowing through the multiple graphene quantum wells/barriers by analyzing the interrelationship among the transmission,bias voltage,incident velocity,and linear potential ranges.The energy minibands and density of states of the graphene superlattices with different periods are also examined by using analytical and numerical methods,showing that the period of superlattices plays a crucial role in energy bands and density of states.
基金Supported by the National Natural Science Foundation of China under Grant No.60776062the Shanxi Scholarship Council of China+1 种基金the Natural Science Foundation of Shanxi Province under Grant No.2008011001-2the National Fundamental Fund of Personnel Training under Grant No.J1103210.
文摘The single-electron tunneling processes in optically excited coupled quantum dots can be divided into two parts:the electron and the hole parts,which are analytically obtained in the framework of the Keldysh formalism.The tunneling process is selective tunneling,which results in dark tunneling states.The tunneling currents are co-determined by the resonance energies and probability distributions of the particular quantum channels defined by the electron-hole complex resonant states.
基金Supported in part by the National Natural Science Foundation of China under Grant No.19725417the Grant of China Academy of Engineering and Physics。
文摘Based on a two-band tight-binding model,the dynamics of electrons under the action of static electric fields with Markoffian dephasing is investigated.The effective scattering time is obtained under the conditions of long-time limit and small interband communication through a perturbative calculation,from which the signature of Zener resonances and relatively long time evolution behavior are predicted.
