Enhanced Rashba effect for hole states in a quantum dot

Manaselyan, Aram; Chakraborty, Tapash

doi:10.1209/0295-5075/88/17003

Cited by 23 publications

(23 citation statements)

References 44 publications

(55 reference statements)

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“…All single hole energy levels and expansion coefficients are evaluated numerically using the exact diagonalization scheme [19]. Calculations are carried out for the CdTe quantum dot with sizes a e = a h = 37Å, L = 25Å and with following parameters: E g = 1.59 eV, m e = 0.096m 0 , g e = −1.5 γ 1 = 5.29, γ 2 = 1.8, γ 3 = 2.46, κ = 0.7 [20].…”

Section: The Single-electron Energy Is Given Bymentioning

confidence: 99%

Spin interactions in a quantum dot containing a magnetic impurity

Manaselyan

Chakraborty

2010

Nanotechnology

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Abstract. The electron and hole states in a CdTe quantum dot containing a single magnetic impurity in an external magnetic field are investigated, using the multiband approximation which includes the heavy hole-light hole coupling effects. The electronhole spin interactions and s,p-d interactions between the electron, the hole and the magnetic impurity are also included. The exciton energy levels and optical transitions are evaluated using the exact diagonalization scheme. A novel mechanism is proposed here to manipulate impurity-spin in the quantum dot which allows us to drive selectively the spin of the magnetic atom into each of its six possible orientations.

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Section: The Single-electron Energy Is Given Bymentioning

confidence: 99%

Spin interactions in a quantum dot containing a magnetic impurity

Manaselyan

Chakraborty

2010

Nanotechnology

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“…O segundo efeito sobre a estrutura electrônica vem da interação spin-órbita induzida por strain, chamada de engenharia de strain, para manipulção de spin em estado sólido. Este tipo de manipulação tem sido usado em experimentos de controle de spin eletrônico, tais como na precessão e coerência de spin, propriedades de transporte entre outras (NADJ-PERGE et al, 2010;JHA et al, 2014).…”

Section: Introductionunclassified

Influência do Strain e da Interação Spin-Órbita em um Ponto Quântico Cilíndrico

Prado¹

2015

Semina: Tech. Ex.

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In this work study how the strain and spin-orbit Rashba interaction type affect the energy levels of the conduction band in a cylindrical quantum dot, using the 2x2 method k•p. The results show that the spinorbit interaction strongly influences the energy levels of lifting the degeneracy even in zero magnetic field, while the strain compressing the levels enhance the Rashba interaction effects. In this context, the intraband optic absorption becomes a useful tool to study the effects of spin-orbit interaction and the strain on the electron energy levels. ResumoNeste trabalho estudo como o strain e a interação spin-órbita Rashba afetam os níveis de energia da banda de condução em um ponto quântico cilíndrico submetido a um campo magnético externo, usando o método k•p 2x2. Os resultados apresentados mostram que a interação spin-órbita influencia fortemente os níveis de energia levantando a degenerescência mesmo em campo magnético nulo, enquanto que o strain comprime os níveis aumentando os efeitos da interação Rashba. Neste contexto, a absorção óptica intrabanda vem a ser uma ferramenta útil para se estudar os efeitos da interação spin-órbita e do strain sobre os níveis de energia dos elétrons.

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“…For a given value of F z it is logical to seek the eigenfunctions of the Hamiltonian (5) as an expansion [14,16] …”

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confidence: 99%

“…All single hole energy levels and the expansion coefficients are evaluated numerically using the exact diagonalization scheme [16].…”

mentioning

confidence: 99%

Tuning of exciton states in a magnetic quantum ring

Ghazaryan¹,

Manaselyan²,

Chakraborty³

2015

Physica E: Low-dimensional Systems and Nanostructures

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We have studied the exciton states in a CdTe quantum ring in an external magnetic field containing a single magnetic impurity. We have used the multiband approximation which includes the heavy hole -light hole coupling effects. The electron-hole spin interactions and the s, p − d interactions between the electron, hole and the magnetic impurity are also included. The exciton energy levels and optical transitions are evaluated using the exact diagonalization scheme. We show that due to the spin interactions it is possible to change the bright exciton state into the dark state and vice versa with the help of a magnetic field. We propose a new route to experimentally estimate the s, p − d spin interaction constants.Electronic properties of planar nanoscale semiconductor structures, such as quantum rings (QRs) [1] and quantum dots (QDs) [2] have enjoyed widespread attention in the past few decades due to their novel fundamental effects and for potential technological applications. Experimental advances in creating these structures from a two-dimensional electron gas by using suitable confinements have resulted in confirmation of several theoretical predictions in these systems [3,4]. It has been realized lately that QD doped with a single magnetic impurity [5][6][7] has great potential to contribute significantly in the burgeoning field of single spin manipulation [8], which will eventually lead to important contributions in quantum information processing. Quite naturally, quantum dots, in particular the CdTe QDs containing a single Mn atom has been widely studied in the literature [9]. It has been proposed that magnetic doping of QDs provides an interesting route to magnetism in the QDs that can be tuned [10]. Against the backdrop of these important developments, no such studies involving a quantum ring have been reported yet in the literature. Recently, CdTe QRs have been realized experimentally [11]. Here we report on our studies of the exciton states in a CdTe QR in a magnetic field, containing a single magnetic impurity. We have found that, due to the resulting spin interactions the bright exciton state can be changed to the dark state and vice versa, with the help of an applied magnetic field. Additionally, we propose here an experimental means to estimate the s, p − d spin interaction constants.We study the exciton states in a CdTe quantum ring containing a single manganese magnetic impurity (Mn) and subjected to a perpendicular magnetic field. Usually, the thickness of the ring is smaller than the radial dimensions. Therefore, our system can be considered as quasi two-dimensional, with internal radius R 1 and the external radius R 2 . The electron and hole are always in the ground state for the z direction. We chose the confinement potential of the quantum ring in the radial direction with infinitely high borders: V conf (ρ) = 0 if R 1 ≤ ρ ≤ R 2 and infinity outside of the QR. The Hamiltonian of the system can then be written aswhere H s−d = −J e δ(r e −r Mn )σS and H p−d = −J h δ(r h − r Mn )jS describe the...

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Enhanced Rashba effect for hole states in a quantum dot

Cited by 23 publications

References 44 publications

Spin interactions in a quantum dot containing a magnetic impurity

Spin interactions in a quantum dot containing a magnetic impurity

Influência do Strain e da Interação Spin-Órbita em um Ponto Quântico Cilíndrico

Tuning of exciton states in a magnetic quantum ring

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