tailieunhanh - Báo cáo hóa học: " Binding Energy of Hydrogen-Like Impurities in Quantum Well Wires of InSb/GaAs in a Magnetic Field"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Binding Energy of Hydrogen-Like Impurities in Quantum Well Wires of InSb/GaAs in a Magnetic Field | Nanoscale Res Lett 2007 2 515-518 DOI s11671-007-9084-2 NANO EXPRESS Binding Energy of Hydrogen-Like Impurities in Quantum Well Wires of InSb GaAs in a Magnetic Field B. Zh. Poghosyan Received 19 May 2007 Accepted 27 July 2007 Published online 22 September 2007 to the authors 2007 Abstract The binding energy of a hydrogen-like impurity in a thin size-quantized wire of the InSb GaAs semiconductors with Kane s dispersion law in a magnetic field B parallel to the wire axis has been calculated as a function of the radius of the wire and magnitude of B using a variational approach. It is shown that when wire radius is less than the Bohr radius of the impurity the nonparabolicity of dispersion law of charge carriers leads to a considerable increase of the binding energy in the magnetic field as well as to a more rapid growth of binding energy with growth of B. Keywords Quantum well wire QWW Hydrogenlike impurity Binding energy Magnetic confinement Introduction The investigation of shallow impurity and excitonic states in various confined systems such as quantum wells quantum well wires QWW and quantum dots QD 1-3 in external magnetic and electric fields are of great interest for a better understanding of their properties as well as for their potential application in optoelectronic devices 4 5 . Photospectroscopy experiments carried out on n-type GaAs in magnetic fields have revealed transitions involving the so-called metastable impurity states 6 . These states associated with the free electron Landau levels modified by the Coulomb interaction between the donor ion and electron are known as Landau-like states 7 . B. Zh. Poghosyan El Gyumri State Pedagogical Institute 4 P. Sevak street Gyumri 3126 Armenia In earlier work Zhilich and Monozon 8 variational procedure to calculate the energies of Landau-like states of shallow donors is used. However this method applies only for extreme values of magnetic field. The variational method of investigating these states were