Sub-cycle control of multi-THz high-harmonic generation and all-coherent charge transport in bulk semiconductors

被引：0

作者：

Lange, C. ^{[1
]}

Schubert, O. ^{[1
]}

Hohenleutner, M. ^{[1
]}

Langer, F. ^{[1
]}

Baierl, S. ^{[1
]}

Maag, T. ^{[1
]}

Urbanek, B. ^{[1
]}

Edwards, E. R. J. ^{[2
]}

Woltersdorf, G. ^{[1
,2
]}

Bougeard, D.

Huttner, U. ^{[3
]}

Golde, D. ^{[3
]}

Meier, T. ^{[4
]}

Kira, M. ^{[3
]}

Koch, S. W. ^{[3
]}

Huber, R. ^{[1
]}

机构：

[1] Univ Regensburg, Dept Phys, D-93040 Regensburg, Germany

[2] Univ Halle Wittenberg, Dept Phys, D-06120 Halle, Germany

[3] Univ Marburg, Dept Phys, D-35032 Marburg, Germany

[4] Univ Paderborn, Dept Phys, D-33098 Paderborn, Germany

来源：

NONLINEAR FREQUENCY GENERATION AND CONVERSION: MATERIALS, DEVICES, AND APPLICATIONS XIV | 2015年 / 9347卷

关键词：

Bloch Oscillations; Terahertz High-Harmonic Generation; Ultrafast Zener Tunneling; BLOCH OSCILLATIONS; TERAHERTZ PULSES;

D O I：

10.1117/12.2085101

中图分类号：

TM [电工技术]; TN [电子技术、通信技术];

学科分类号：

0808 ; 0809 ;

摘要：

Ultrafast transport of electrons in semiconductors lies at the heart of high-speed electronics, electro-optics and fundamental solid-state physics. Intense phase-locked terahertz (THz) pulses at photon energies far below electronic interband resonances may serve as a precisely adjustable alternating bias, strongly exceeding d.c. breakdown voltages. Here, we exploit the near-field enhancement in gold metamaterial structures on undoped bulk GaAs, driven by few-cycle THz transients centered at 1 THz, to bias the semiconductor substrate with field amplitudes exceeding 12 MV/cm. Such fields correspond to a potential drop of the bandgap energy over a distance of only two unit cells. In this extremely off-resonant scenario characterized by a Keldysh parameter of. gamma(K) approximate to 0.02, massive interband Zener tunneling injects a sizeable carrier density exceeding 10(19) cm(-3), and strong photoluminescence results. At a center frequency of 30 THz, THz transients with peak fields of 72 MV/cm analogously excite carriers in a bulk, semiconducting GaSe crystal, without metamaterial. Here, in contrast, we are able to drive coherent interband polarization and furthermore dynamical Bloch oscillations of electrons in the conduction band, on femtosecond time scales. The dynamics entail the generation of absolutely phase-stable high-harmonic transients containing spectral components up to the 22nd order of the fundamental frequency, spanning 12.7 optical octaves throughout the entire terahertz-to-visible domain between 0.1 and 675 THz. Our experiments establish a new field of light-wave electronics exploring coherent charge transport at optical clock rates and bring picosecond-scale electric circuitry at the interface of THz optics and electronics into reach.

引用

页数：6