Institute for Physics of Microstructures RAS, GSP-105, 603950, Nizhny Novgorod, Russia.
J Phys Condens Matter. 2012 Apr 4;24(13):135601. doi: 10.1088/0953-8984/24/13/135601. Epub 2012 Mar 9.
Using the 'screened' Hartree-Fock approximation based on the eight-band k·p Hamiltonian, we have extended our previous work (Krishtopenko et al 2011 J. Phys.: Condens. Matter 23 385601) on exchange enhancement of the g-factor in narrow-gap quantum well heterostructures by calculating the exchange renormalization of quasiparticle energies, the density of states at the Fermi level and the quasiparticle g-factor for different Landau levels overlapping. We demonstrate that exchange interaction yields more pronounced Zeeman splitting of the density of states at the Fermi level and leads to the appearance of peak-shaped features in the dependence of the Landau level energies on the magnetic field at integer filling factors. We also find that the quasiparticle g-factor does not reach the maximum value at odd filling factors in the presence of large overlapping of spin-split Landau levels. We advance an argument that the behavior of the quasiparticle g-factor in weak magnetic fields is defined by a random potential of impurities in narrow-gap heterostructures.
利用基于八能带 k·p 哈密顿量的“筛选”Hartree-Fock 近似，我们扩展了之前的工作（Krishtopenko 等人，2011 年，《物理：凝聚态物质》，23，385601），通过计算不同 Landau 能级重叠时准粒子能量、费米能级处的态密度和准粒子 g 因子的交换重整化，研究了窄能隙量子阱异质结构中 g 因子的交换增强。我们证明，交换相互作用导致费米能级处的态密度产生更明显的塞曼劈裂，并导致在整数填充因子下， Landau 能级能量对磁场的依赖关系出现峰形特征。我们还发现，在自旋分裂的 Landau 能级有很大重叠的情况下，准粒子 g 因子在奇数填充因子时不会达到最大值。我们提出一个论点，即弱磁场中准粒子 g 因子的行为由窄能隙异质结构中杂质的随机势决定。
