Binding Energies of Hydrogen-Like Impurities in a Semiconductor in Intense Terahertz Laser Fields

Abstract

We present a detailed theoretical study of the influence of linearly polarised intense terahertz (THz) laser radiation on energy states of hydrogen-like impurities in semiconductors. The dependence of the binding energy for ground (1s) and first excited (2s) states, E 1s and E 2s , on intensity and frequency of the THz radiation has been examined for a GaAs-based system. It is found that E 1s , E 2s and E 2s − E 1s decrease with increasing radiation intensity or with decreasing radiation frequency, which implies that an intense THz field can enhance ionisation of dopants in semiconductors. Our analytical and numerical results show that one of the most important results obtained by A.L.A. Fonseca et al [phys. stat. sol. (b) 186, K57 (1994)] is incorrect.

Increase of the positronium lifetime under high-frequency, intense laser fields

“…By noting that, for F 0 , 1 V m −1 = 10 −5 kV cm −1 and, for I, 1 W m −2 = 10 −7 kW cm −2 , one has F 0 ≈ 0.868 √ I , for F 0 in kV cm −1 and I in kW cm −2 . This is in agreement with the formula derived in [34] (see its [14]). For a practical formula for the laser-dressing parameter, we start by dividing both sides of α 0 = eF 0 /(μω 2 ) by the Ps Bohr radius, namely h2 /(μke 2 ).…”

Density of impurity states of shallow donors in a quantum well under intense laser field

“…In a bulk semiconductor irradiated by a linearly polarized laser field the binding energy of a hydrogenic impurity should decrease monotonically with the increase of the laser intensity [1]. Lima et al argued that by choosing appropriate trial wave functions, the impurity becomes stable against ionization in the high-intensity limit, for a given frequency [2].…”