Sub-cycle control of terahertz high-harmonic generation by dynamical Bloch oscillations
Sub-cycle control of terahertz high-harmonic generation by dynamical Bloch oscillations
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DOI：
10.1038/nphoton.2013.349
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发表时间：
2014-02-01
期刊：
影响因子：
35
通讯作者：
Huber, R.
中科院分区：
文献类型：
--
作者：
Schubert, O.;Hohenleutner, M.;Huber, R.
强偏置半导体中的超快电荷传输是高速电子学、电光学和基础固态物理学的核心(1-13)。太赫兹光谱范围内的强光脉冲开启了迷人的前景(14-21)。由于太赫兹光子能量远低于典型的电子带间谐振，因此稳定的电磁波形可以作为精确可调的偏置(5,11,17,19)。太赫兹振幅预计会出现新的量子现象，达到原子场强度 (8-10)。我们利用峰值场为 72 MV cm(-1) 的受控（多）太赫兹波形来驱动半导体硒化镓中的相干带间偏振与动态布洛赫振荡相结合。这些动力学需要发射相位稳定的高次谐波瞬态，覆盖 0.1 至 675 THz 之间的整个太赫兹到可见光谱域。加速电荷载流子的不同电离路径的量子干涉通过驱动场的波形进行控制，并通过带间和带内动力学的量子理论进行解释。我们的结果为全相干太赫兹速率电子学铺平了道路。
Ultrafast charge transport in strongly biased semiconductors is at the heart of high-speed electronics, electro-optics and fundamental solid-state physics(1-13). Intense light pulses in the terahertz spectral range have opened fascinating vistas(14-21). Because terahertz photon energies are far below typical electronic interband resonances, a stable electromagnetic waveform may serve as a precisely adjustable bias(5,11,17,19). Novel quantum phenomena have been anticipated for terahertz amplitudes, reaching atomic field strengths(8-10). We exploit controlled (multi-)terahertz waveforms with peak fields of 72 MV cm(-1) to drive coherent interband polarization combined with dynamical Bloch oscillations in semiconducting gallium selenide. These dynamics entail the emission of phase-stable high-harmonic transients, covering the entire terahertz-to-visible spectral domain between 0.1 and 675 THz. Quantum interference of different ionization paths of accelerated charge carriers is controlled via the waveform of the driving field and explained by a quantum theory of inter- and intraband dynamics. Our results pave the way towards all-coherent terahertz-rate electronics.