Bloch-phonon coupling and tunneling-induced coherent phonon excitation in semiconductor superlattices
Bloch-phonon coupling and tunneling-induced coherent phonon excitation in semiconductor superlattices
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半导体超晶格中的布洛赫声子耦合和隧道诱导相干声子激发
DOI：
10.1103/physrevb.67.085305
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发表时间：
2003
影响因子：
3.7
通讯作者：
R. Leavitt
中科院分区：
文献类型：
--
作者：
M. Först;H. Kurz;T. Dekorsy;R. Leavitt
本文研究了在0。5 3 Ga0.4 7 AS/In 0.5 2 Al 0.4 8为超晶格。当随后将Bloch振荡调谐为具有不同光学声子模式的共振时，观察到相干声子幅度的显著增加。由于场诱导隧穿使Bloch振荡从弱束缚微带进入势垒以上连续态，使Bloch振荡快速退位相，导致了高电场下超晶格中相干声子的新的激发过程。偏振相关测量证实了它们是通过库仑相互作用产生的，不包括脉冲受激拉曼散射的任何贡献。
The coupling of Bloch oscillations to longitudinal optical phonons is investigated in a narrow-well In 0 . 5 3 Ga 0 . 4 7 As/In 0 . 5 2 Al 0 . 4 8 As superlattice. A strong increase of coherent phonon amplitudes is observed when the Bloch oscillations are subsequently tuned into resonance with different optical phonon modes. The rapid dephasing of the Bloch oscillations due to field induced tunneling from the weakly bound miniband into above-barrier continuum states leads to an additional and new excitation process of coherent phonons in superlattices at high electric fields. Polarization dependent measurements confirm their generation via Coulomb interaction excluding any contribution through impulsively stimulated Raman scattering.