Low-temperature transport in CdS disordered quantum wires: dephasing
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ORIGINAL PAPER
Low-temperature transport in CdS disordered quantum wires: dephasing E Rostampour* Young Researchers and Elites Club, Science and Research Branch, Islamic Azad University, Tehran, Iran Received: 19 October 2019 / Accepted: 09 June 2020
Abstract: We study the effect of disorder and dephase in transmission of a CdS quantum wire using the Green’s function technique. Our results show that the transmission decreases with the increasing disorder strength. The resistance of a CdS quantum wire with phase-breaking scattering only increases with increasing dephasing. Obtained results show that the drain current of a CdS quantum wire with inelastic scattering by phonons with energy hx ¼ 30 meV decreases with the increasing disorder strength. Moreover, our theoretical results are independently supported by simulations of CdS disordered quantum wires based on a tight-binding model. Keywords: Low-temperature transport; CdS disordered quantum wires; Dephasing
1. Introduction Quasi-one-dimensional systems are currently attracting a great deal of interest for their potential applications in high-speed electron devices and extremely low-thresholdcurrent lasers [1–4]. Conduction quantization is a hallmark effect of ballistic one-dimensional noninteracting electrons [5–8]. One mode of conductance e2/h opens for each spin, giving conductance steps of 2e2/h for spin degenerate electrons. In the presence of electron–electron (e–e) interactions, strongly correlated electron behavior arises, described by Luttinger liquid theory [9–11]. In the ballistic electron transport, the conductance is quantized in units of the quantum G0 = 2e2/h. The two-dimensional electron states are quantized in the direction perpendicular to the axis of the wire. Each occupied perpendicular state gives rise to one conducting mode adding one quantum to the conductance. In a typical measurement, the conductance is recorded as a function of the gate voltage which lowers the potential in the wire region, influencing its width or the average electron density. The increase in the number of conducting modes results in a staircase as a function of the gate voltage. Recently, Kane et al. [12] and Reilly et al. [13] have measured conductance of quantum wires with different geometries. The quantization of the conductance
*Corresponding author, E-mail: [email protected]
is clearly seen in the measurements. However, electronic devices such as quantum dots and quantum wires have proposed to produce entanglement of electrons without interactions [14, 15]. Energy spectra of charge carriers and excitons in quantum wires with rectangular, T-shaped, V-groove and other cross sections have studied [16–22]. In one-dimensional systems, disorder has a dramatic effect, since it localizes the electrons in the sense that the transmission decays exponentially with length. This purely quantum mechanical fundamental phenomenon is referred to as Anderson localization [23]. Random-matrix theory has successfully applied to study different statistical properties of sca
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