A loop diagram approach to the nonlinear optical conductivity of an electron-phonon system is introduced. This approach can be categorized as another Feynman-like scheme because all contributions to the self-energy te...A loop diagram approach to the nonlinear optical conductivity of an electron-phonon system is introduced. This approach can be categorized as another Feynman-like scheme because all contributions to the self-energy terms can be grouped into topologically-distinct loop diagrams. The results for up to the first order nonlinear conductivity are identical to those derived using the KC reduction identity (KCRI) and the state- dependent projection operator (SDPO) introduced by the present authors. The result satisfies the “population criterion” in that the population of electrons and phonons appear independently or the Fermi distributions are multiplied by the Planck distributions in the formalism. Therefore it is possible, in an organized manner, to present the phonon emissions and absorptions as well as photon absorptions in all electron transition processes. In additions, the calculation needed to obtain the line shape function appearing in the energy denominator of the conductivity can be reduced using this diagram method. This method shall be called the “KC loop diagram method”, since it originates from proper application of KCRI’s and SDPO’s.展开更多
Micro/nanoelectromechanical systems(MEMS/NEMS)have potential applications in sensing,cooling,and mechanical signal processing.Thanks to the development of modern MEMS fabrication techniques,in analogy to photons,phono...Micro/nanoelectromechanical systems(MEMS/NEMS)have potential applications in sensing,cooling,and mechanical signal processing.Thanks to the development of modern MEMS fabrication techniques,in analogy to photons,phonons in NEMS attract significant research interests recently.Single-electron tunneling events in quantum-dot-like nanostructures have been widely used in mesoscopic transport studies.Quantum dots are also considered as an ideal candidate platform for solid-state quantum computation.The coupling of these two types of systems has vast application prospects in information storage,transfer and also fundamental physics investigations.The most popular system realizing such coupling is a suspended carbon nanotube,in which the local gates can be used to confine a quantum dot,actuate a resonator and tune the resonant frequency.In this review,we focus on recent progress in this coupled system composed of carbon-based materials and discuss device fabrication,coupling mechanisms,and applications.展开更多
文摘A loop diagram approach to the nonlinear optical conductivity of an electron-phonon system is introduced. This approach can be categorized as another Feynman-like scheme because all contributions to the self-energy terms can be grouped into topologically-distinct loop diagrams. The results for up to the first order nonlinear conductivity are identical to those derived using the KC reduction identity (KCRI) and the state- dependent projection operator (SDPO) introduced by the present authors. The result satisfies the “population criterion” in that the population of electrons and phonons appear independently or the Fermi distributions are multiplied by the Planck distributions in the formalism. Therefore it is possible, in an organized manner, to present the phonon emissions and absorptions as well as photon absorptions in all electron transition processes. In additions, the calculation needed to obtain the line shape function appearing in the energy denominator of the conductivity can be reduced using this diagram method. This method shall be called the “KC loop diagram method”, since it originates from proper application of KCRI’s and SDPO’s.
基金supported by the National Key Research and Development Program of China(Grant No. 2016YFA0301700)the National Natural Science Foundation of China(Grant Nos.11625419,61674132, 11674300,11575172,and 91421303)+1 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB01030000)the Fundamental Research Fund for the Central Universities
文摘Micro/nanoelectromechanical systems(MEMS/NEMS)have potential applications in sensing,cooling,and mechanical signal processing.Thanks to the development of modern MEMS fabrication techniques,in analogy to photons,phonons in NEMS attract significant research interests recently.Single-electron tunneling events in quantum-dot-like nanostructures have been widely used in mesoscopic transport studies.Quantum dots are also considered as an ideal candidate platform for solid-state quantum computation.The coupling of these two types of systems has vast application prospects in information storage,transfer and also fundamental physics investigations.The most popular system realizing such coupling is a suspended carbon nanotube,in which the local gates can be used to confine a quantum dot,actuate a resonator and tune the resonant frequency.In this review,we focus on recent progress in this coupled system composed of carbon-based materials and discuss device fabrication,coupling mechanisms,and applications.
