The intensive terahertz electroluminescence induced by Bloch oscillations in SiC natural superlattices

Nanoscale Research Letters (Impact Factor: 2.78). 10/2012; 7(1):560. DOI: 10.1186/1556-276X-7-560
Source: PubMed


We report on efficient terahertz (THz) emission from high-electric-field-biased SiC structures with a naturalsuperlattice at liquid helium temperatures. The emission spectrum demonstrates a single line, the maximum of which shifts linearly with increases in bias field. We attribute this emission to steady-state Bloch oscillations of electrons in the SiC natural superlattice. The properties of the THz emission agree fairly with the parameters of the Bloch oscillator regime, which have been proven by high-field electron transport studies of SiC structures with natural superlattices.

Download full-text


Available from: Alexander Vasilievich Andrianov, Jun 11, 2015
1 Follower
15 Reads
  • [Show abstract] [Hide abstract]
    ABSTRACT: We solve the time-dependent Schrödinger equation based on the complete Hamiltonian for independent electrons in ideal GaAs/AlxGa1-xAs superlattices, described by the conventional one-dimensional flat-band picture, subject to a uniform electric field F. Our approach consists of using high-accuracy numerical methods, thereby enabling us to avoid truncating the Hamiltonian or adopting other uncontrolled approximations. In suitable circumstances the electrons exhibit long-lived, time-periodic Bloch oscillations, in the form of either sinusoidal center-of-mass oscillations or a coherent breathing mode. Depending on the miniband structure of the superlattice, the value of F, and the form of the initial wave function, other dynamical phenomena can coexist with or even totally mask the Bloch oscillations. These are unbounded acceleration of a portion of the electron wave packet antiparallel to the electric field and intrawell oscillations. We provide the conditions under which each of these three basic dynamical elements occurs. We summarize the major results of our systematic investigation of the dependence of the electron dynamics on the entire parameter space of periodic potentials, field strengths, and initial wave functions.
    Physical review. B, Condensed matter 09/1995; 52(7):5105-5123. DOI:10.1103/PhysRevB.52.5105 · 3.66 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The coherent dynamics of Wannier-Stark (WS) states and localized states in In-Ga-As-P/In-Ga-As-P superlattices is studied with time-resolved transmission experiments. The transmission of the probe is modulated due to the quantum interference of electronic Wannier-Stark states (Bloch oscillations) and the quantum interference of WS states and a growth-induced localized 2D state. Their frequency and decay provide information on the coherent coupling processes which is not accessible with linear optical techniques.
    Physical review. B, Condensed matter 09/1996; 54(7):4420-4423. DOI:10.1103/PhysRevB.54.4420 · 3.66 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: We have observed that a strong electric field scrE shifts to higher energies the photoluminescence and photocurrent peaks of a GaAs-Ga0.65Al0.35As superlattice of period D (=65 A[ring ]), which we explain by a field-induced localization of carriers to isolated quantum wells. Good agreement is found between observed and calculated shifts when the large field-induced increase of the exciton binding energy is taken into account. At moderate fields [~(23) x 104 V/cm], the coupling between adjacent wells is manifested by four additional peaks that shift at the rates escrED and 2escrED and correspond to transitions that involve different levels of the Stark ladder.
    Physical Review Letters 06/1988; 60(23):2426--2429. DOI:10.1103/PhysRevLett.60.2426 · 7.51 Impact Factor
Show more