Lange C, Maag T, Hohenleutner M, Baierl S, Schubert O, Edwards E R J, Bougeard D, Woltersdorf G, Huber R
Department of Physics, University of Regensburg, 93040 Regensburg, Germany.
Department of Physics, Martin-Luther-University Halle-Wittenberg, 06120 Halle, Germany.
Phys Rev Lett. 2014 Nov 28;113(22):227401. doi: 10.1103/PhysRevLett.113.227401. Epub 2014 Nov 26.
Terahertz near fields of gold metamaterials resonant at a frequency of 0.88 THz allow us to enter an extreme limit of nonperturbative ultrafast terahertz electronics: Fields reaching a ponderomotive energy in the keV range are exploited to drive nondestructive, quasistatic interband tunneling and impact ionization in undoped bulk GaAs, injecting electron-hole plasmas with densities in excess of 10^{19} cm^{-3}. This process causes bright luminescence at energies up to 0.5 eV above the band gap and induces a complete switch-off of the metamaterial resonance accompanied by self-amplitude-modulation of transmitted few-cycle terahertz transients. Our results pave the way towards highly nonlinear terahertz optics and optoelectronic nanocircuitry with subpicosecond switching times.
在0.88太赫兹频率处发生共振的金超材料的太赫兹近场，使我们能够进入非微扰超快太赫兹电子学的一个极端极限：利用达到keV范围内有质动力能量的场，在未掺杂的块状砷化镓中驱动非破坏性的准静态带间隧穿和碰撞电离，注入密度超过10^{19} cm^{-3}的电子 - 空穴等离子体。这个过程会在高于带隙0.5电子伏特的能量处产生明亮的发光，并导致超材料共振完全关闭，同时伴随着透射的少周期太赫兹瞬态的自振幅调制。我们的结果为具有亚皮秒开关时间的高度非线性太赫兹光学和光电纳米电路铺平了道路。
