本文研究了 n 型重掺杂 GaAs 中的光生空穴的超快弛豫过程,首次比较详细地在 k 空间对空穴-空穴散射速率进行了尽可能多的解析计算,从而可以看到空穴-空穴散射率与有效质量、掺杂浓度、激发浓度以及激发能量的比较定量的关系,其结果表...本文研究了 n 型重掺杂 GaAs 中的光生空穴的超快弛豫过程,首次比较详细地在 k 空间对空穴-空穴散射速率进行了尽可能多的解析计算,从而可以看到空穴-空穴散射率与有效质量、掺杂浓度、激发浓度以及激发能量的比较定量的关系,其结果表明散射速率随掺杂浓度的增加而减小,随激发浓度的增加而增加。另外,我们在 k 空间也推导了空穴与极性以及与非极性光学声子散射的散射率公式。在实验上,我们测试了在费米能级附近 n 型重掺杂 GaAs 中的光生空穴的弛豫过程,并因此而估算出光学形变势常数 d0约为31eV。展开更多
Based on the Fermi's golden rule and the theory of Boltzmann collision term approximation, a physically-based model for hole scattering rate(SR) in strained Si1-x Gex/(100)Si was presented, which takes into accoun...Based on the Fermi's golden rule and the theory of Boltzmann collision term approximation, a physically-based model for hole scattering rate(SR) in strained Si1-x Gex/(100)Si was presented, which takes into account a variety of scattering mechanisms,including ionized impurity, acoustic phonon, non-polar optical phonon and alloy disorder scattering. It is indicated that the SRs of acoustic phonon and non-polar optical phonon decrease under the strain, and the total SR in strained Si1-x Gex/(100)Si also decreases obviously with increasing Ge fraction(x). Moreover, the total SR continues to show a constant tendency when x is less than 0.3. In comparison with bulk Si, the total SR of strained Si1-x Gex/(100) Si decreases by about 58%.展开更多
Based on the Kubo formalism, the anomalous Hall effect in a magnetic two-dimensional hole gas with cubic-Rashba spin-orbit coupling is studied in the presence of δ-function scattering potential. When the weak, shortr...Based on the Kubo formalism, the anomalous Hall effect in a magnetic two-dimensional hole gas with cubic-Rashba spin-orbit coupling is studied in the presence of δ-function scattering potential. When the weak, shortranged disorder scattering is considered in the Born approximation, we find that the self-energy becomes diagonal in the helicity basis and its value is independent of the wave number, and the vertex correction to the anomalous Hall conductivity due to impurity scattering vanishes when both subbands are occupied. That is to say, the anomalous Hall effect is not vanishing or influenced by the vertex correction for two-dimensional heavy-hole system, which is in sharp contrast to the case of linear-Rashba spin-orbit coupling in the electron band when the short-range disorder scattering is considered and the extrinsic mechanism as well as the effect of external electric field on the SO interaction are ignored.展开更多
文摘本文研究了 n 型重掺杂 GaAs 中的光生空穴的超快弛豫过程,首次比较详细地在 k 空间对空穴-空穴散射速率进行了尽可能多的解析计算,从而可以看到空穴-空穴散射率与有效质量、掺杂浓度、激发浓度以及激发能量的比较定量的关系,其结果表明散射速率随掺杂浓度的增加而减小,随激发浓度的增加而增加。另外,我们在 k 空间也推导了空穴与极性以及与非极性光学声子散射的散射率公式。在实验上,我们测试了在费米能级附近 n 型重掺杂 GaAs 中的光生空穴的弛豫过程,并因此而估算出光学形变势常数 d0约为31eV。
基金Project(JY0300122503)supported by the Research Fund for the Doctoral Program of Higher Education of ChinaProject(P140c090303110c0904)supported by NLAIC Research Fund,ChinaProjects(K5051225014,7214608503)supported by the Fundamental Research Funds for the Central Universities,China
文摘Based on the Fermi's golden rule and the theory of Boltzmann collision term approximation, a physically-based model for hole scattering rate(SR) in strained Si1-x Gex/(100)Si was presented, which takes into account a variety of scattering mechanisms,including ionized impurity, acoustic phonon, non-polar optical phonon and alloy disorder scattering. It is indicated that the SRs of acoustic phonon and non-polar optical phonon decrease under the strain, and the total SR in strained Si1-x Gex/(100)Si also decreases obviously with increasing Ge fraction(x). Moreover, the total SR continues to show a constant tendency when x is less than 0.3. In comparison with bulk Si, the total SR of strained Si1-x Gex/(100) Si decreases by about 58%.
基金Supported by the Research Fund for Outstanding Young Teachers in Higher Education Institutions of Shanghai under Grant No.gjd08040the Scientific Research Startup Funds of SUESthe National Natural Science Foundation of China under Grant No.C-6201-10-001
文摘Based on the Kubo formalism, the anomalous Hall effect in a magnetic two-dimensional hole gas with cubic-Rashba spin-orbit coupling is studied in the presence of δ-function scattering potential. When the weak, shortranged disorder scattering is considered in the Born approximation, we find that the self-energy becomes diagonal in the helicity basis and its value is independent of the wave number, and the vertex correction to the anomalous Hall conductivity due to impurity scattering vanishes when both subbands are occupied. That is to say, the anomalous Hall effect is not vanishing or influenced by the vertex correction for two-dimensional heavy-hole system, which is in sharp contrast to the case of linear-Rashba spin-orbit coupling in the electron band when the short-range disorder scattering is considered and the extrinsic mechanism as well as the effect of external electric field on the SO interaction are ignored.
