各向异性量子点中的二维磁极化子效应

Polaron effects on a two-dimension al anisotropic parabolic quantum dot in a perpendi c ular magnetic field

本文研究了在垂直均匀磁场下各向异性量子点中具有中等电子-声子耦合强度的二维磁极化子效应.构造一个变分波函数,它由两部分的乘积组成,第一部分是相干声子态,由对声子真空态的Lee-Low-Pines变换得来;第二部分是电子波函数,由二维各向异性谐振子波函数通过特殊幺正变换得来.然后通过变分法获得极化子能谱的积分表达式.利用数值计算的结果,阐明了磁场和各向异性对小尺寸量子点的基态和第一、第二激发态能量的影响.

The polaronic effects under a perpendicula r uniform magnetic field in two-dimensional anisotropic parabolic quantum dots are studied for a n intermediate electron-phon on coupling strength. A variational wave function is constructed as a product form of a part of coherent phonons generated by the Lee-Low-Pines transformation from the vacuum and an electronic part, with the latter being a special unitary transformation from the wave function of a two-dimensional simple anisotropic harmonic oscillator. Integral expressions for th e polaron energy spectrum are obtained by the minimization procedure. After evaluating the results numerically, the magnetic and anisotropic ef fects for the ground and first two excited states of small size quantum dots are demonstrated.