Control of a double quantum dot structure by stimulated Raman adiabatic passage

Abstract

In this work we study the potential for coherent manipulation of an asymmetric double quantum dot structure by the use of adiabatic methods. These methods are the Stimulated Raman Adiabatic Passage (STIRAP) and its modification the fractional STIRAP. We show that such a method can be used for complete electron transfer between the two lower states of the quantum dots. In addition, with fractional STIRAP a coherent superposition of the two lower states of the quantum dots can be created.1 Introduction The interaction of electrons confined in double quantum dot structures with electromagnetic driving fields has attracted much attention in the past decade [1][2][3][4]. Several interesting phenomena have been recognized when the quantum dot structure contains one or two electrons. Examples include controlled transfer of electrons between the two quantum dots [1,3] and creation of maximally entangled states in two-electron quantum dot systems [2,4]. These effects are of central interest in the topical area of quantum computation as quantum dots are artificially created structures with potential scalability, so they are one of the most important candidates for realizing solid state quantum computation.In this work we study the potential for coherent manipulation of an asymmetric double quantum dot structure [3,4] by the use of adiabatic methods. These methods are the Stimulated Raman Adiabatic Passage (STIRAP) [5] and its modification the fractional STIRAP [6]. In STIRAP two electromagnetic pulses are applied in the quantum dot structure in a counter-intuitive sequence [5]. These pulses are also partially overlapping. We show that such a method can be used for complete electron transfer between the two lower levels of the quantum dots. In fractional STIRAP, in addition to the previous procedure, the pulses are also switched-off simultaneously [6]. In this case a coherent superposition of the two lower levels of the quantum dots can be created. We note that several studies in the past five years have applied STIRAP and fractional STIRAP for the control of the dynamics of semiconductor nanostructures [7]. The results of the present paper is a direct application of STIRAP in a double quantum dot structure. The results of this paper can be also directly applied to the asymmetric quantum dot structures of Ref. [3].

Stimulated Raman adiabatic passage in physics, chemistry, and beyond

“…• coherent manipulation of an asymmetric double-QD structure (Voutsinas et al, 2007) and coherent electron transfer between the ground states of two coupled QDs (Fountoulakis and Paspalakis, 2013).…”

Ultrafast single-electron transfer in coupled quantum dots driven by a few-cycle chirped pulse

“…1. [29][30][31][32][33][34][35][36][37][38] The device is composed of two nonidentical quantum dots, marked as left (L) and right (R) dots, respectively. Usually, the coupled QD structures are described as a quasi-one-dimensional problem.…”

“…13 To date, the effect of time-varying external fields on electronic population transfer in semiconductor QD systems has attracted considerable attention and manifest some interesting effects ranging from photon-assisted tunneling to electron pumping. Many theoretical and experimental schemes for controlling transfer of one-electron or twoelectron in coupled QD system have been reported, [22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40] and experimental methods to determine the interdot tunnel coupling both for ground and excited states have been developed. 23,24 As an example, stimulated Raman adiabatic passage (STIRAP) is a very popular method to produce completed population transfer in the quantum dot structure.…”

“…23,24 As an example, stimulated Raman adiabatic passage (STIRAP) is a very popular method to produce completed population transfer in the quantum dot structure. [25][26][27][28][29][30] The STIRAP technique uses the counter-intuitive delayed laser pulses to adiabatically correlate the initial populated state to the desired target state during the system evolution. However, the adiabatic condition limits the pulse width in the nanosecond time scale.…”

Nutation oscillations of an electromagnetic wave propagating through an ensemble of quantum dots

“…Thus, an electron transfer between levels of identical quantum dots at one-photon resonance was considered in [1][2][3][4][5][6][7][8], and [9][10][11][12] treated transfer processes at a combinational and two-photon resonance between discrete levels of an electron system of two quantum dots with essentially different energies. In [13] the case is considered when the levels relating to two different but not necessary identical quantum dots possess approximately similar energy, and it was shown that the system is enough to be affected by electromagnetic field with only one carrier frequency for an electron transfer between quantum dots, and it is not obligatory for any resonance condition to be obeyed.…”