Intervalley Scattering

In the 2DEG intervalley scattering causes transitions to valleys belonging to either the same or to different subband ladders. Following Price's treatment for intravalley optical phonon scattering the transition rate for transitions between different valleys becomes

$$\{ S_\eta^{\tiny\shortstack{abs \\ [-2pt] emi }} \} ^{v'v}_{n'n} ... ...k}}}') - E_n^{v}({\ensuremath{\mathitbf{k}}}) \mp \hbar \omega_\eta \right ]\ ,$$ (5.29)

where $v$ and $v'$ denote the valley index before and after the transition, respectively [Price81,Jungemann93]. A summation is performed over all final valleys $v'$ which are determined by the selection rules for phonon mode $\eta$.

Using the effective mass approximation, the scattering rate for intervalley transitions from an electron in valley $v$ and subband $n$ can be written as (5.22)

$$\{ S_\eta^{\tiny\shortstack{abs \\ [-2pt] emi }} \} _{n}^{v} (E) ... ...2} \mp \frac{1}{2} \right ) g_{n'}^{v'}(E\pm \hbar \omega_\eta-E_{n'}^{v'} )\ .$$ (5.30)

E. Ungersboeck: Advanced Modelling Aspects of Modern Strained CMOS Technology