Mn-doped InAs self-organized diluted magnetic quantum-dot layers with Curie temperatures above 300K

Holub, M.; Chakrabarti, Subhananda; Fathpour, Sasan; Bhattacharya, P.; Yi, Lei; Ghosh, Siddhartha Sankar

doi:10.1063/1.1781361

Cited by 84 publications

(72 citation statements)

References 19 publications

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“…In the bulk-like dilute magnetic semiconductors the carrier-mediated ferromagnetism can be photoinduced [10,11] and electrically controlled by gate electrodes [12], suggesting possible nonvolatile devices with tunable optical, electrical, and magnetic properties [9]. QDs allow for a versatile control of the number of carriers, spin, and the effects of quantum confinement which could lead to improved optical, transport, and magnetic properties as compared to their bulk counterparts [1,13,14]. Unlike in the bulk structures, adding a single carrier in a magnetic QD can have important ramifications.…”

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confidence: 99%

Tailoring Magnetism in Quantum Dots

2007

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We study magnetism in magnetically doped quantum dots as a function of confining potential, particle numbers, temperature, and strength of Coulomb interactions. We explore possibility of tailoring magnetism by controlling the electron-electron Coulomb interaction, without changing the number of particles. The interplay of strong Coulomb interactions and quantum confinement leads to enhanced inhomogeneous magnetization which persist at higher temperatures than in the noninteracting case. The temperature of the onset of magnetization can be controlled by changing the number of particles as well as by modifying the quantum confinement and the strength of Coulomb interactions. We predict a series of electronic spin transitions which arise from the competition between the many-body gap and magnetic thermal fluctuations.PACS numbers: 75.75.+a,75.50.Pp, Magnetic doping of semiconductor quantum dots (QDs) provides an interesting interplay of interaction effects in confined geometries [1,2,3,4,5,6,7,8] and potential spintronic applications [9]. In the bulk-like dilute magnetic semiconductors the carrier-mediated ferromagnetism can be photoinduced [10,11] and electrically controlled by gate electrodes [12], suggesting possible nonvolatile devices with tunable optical, electrical, and magnetic properties [9]. QDs allow for a versatile control of the number of carriers, spin, and the effects of quantum confinement which could lead to improved optical, transport, and magnetic properties as compared to their bulk counterparts [1,13,14]. Unlike in the bulk structures, adding a single carrier in a magnetic QD can have important ramifications. An extra carrier can both strongly change the total carrier spin and the temperature of the onset of magnetization which we show can be further controlled by modifying the quantum confinement and the strength of Coulomb interactions.We study the magnetic ordering of carrier spin and magnetic impurities in (II,Mn)VI QDs identified as a versatile system to demonstrate interplay of quantum confinement and magnetism [4,5,6,15,16,17,18]. Because Mn is isoelectronic with group-II elements it does not change the number of carriers which in QDs are controlled by either chemical doping or by external electrostatic potential applied to the metallic gates. The latter allows confinement of the carriers in a dot with tunable size and shape [2]. By using real space finite-temperature local spin density approximation (LSDA) [19] we study temperature (T ) evolution of magnetic properties of QDs over a large parameter space. This approach allow us to consider QDs with varying number of interacting electrons (N ) and Mn impurities (N m ) which already for small N and N m becomes computationally inaccessible to the exact diagonalization techniques [18,20]. We extend the previous studies of Coulomb interactions in magnetic QDs with N m = 1, 2 at T = 0 [18] and T > 0 results using either Thomas-Fermi approximation or by applying Hund's rule with up to 6 carriers [17]. We reveal that the interplay of strong Cou...

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confidence: 99%

Tailoring Magnetism in Quantum Dots

2007

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“…Для стабилизации поверх-ности роста КТ и снижения разброса по размерам при-меняется легирование различными примесями. Влияние легирования на особенности самоорганизации КТ иссле-довалось в ряде работ [8][9][10][11]. Модификация механизма формирования КТ вносит контролируемые изменения в их свойства.…”

Section: (поступило в редакцию 12 июля 2016 г)unclassified

“…Например, легирование висмутом КТ в про-цессе роста, выполненное в [8], привело к модификации механизма самоорганизации и формированию массива КТ с меньшей шириной спектральной линии. Легиро-вание атомами Mn, выполненное в [10,11], применяется для придания массиву КТ ферромагнитных свойств.…”

Section: (поступило в редакцию 12 июля 2016 г)unclassified

“…Введение указанных примесей используется для формирования структур спинтроники с целью управле-ния спином носителей заряда в КТ, содержащих при-месь Mn(Cr). Особенностью изготовленных структур по сравнению с [10][11][12] является применение метода газо-фазной эпитаксии [9,13]. Целями исследования являлись: изучение механизмов формирования КТ в присутствии примеси переходного элемента и поиск путей контроли-руемого управления свойствами структур с КТ, форми-руемыми методом МОС-гидридной эпитаксии.…”

Section: (поступило в редакцию 12 июля 2016 г)unclassified

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Гетероструктуры с квантовыми точками InGaAs/GaAs, легированными атомами переходных элементов. I. Фотолюминесцентные свойства

Дорохин¹,

Здоровейщев²,

Малышева³

et al. 2017

Журнал Технической Физики

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“…1,2 The growth of magnetic II/VI QDs is well established in contrast to the situation for III/V magnetic QDs. Although several groups [3][4][5][6] have reported on the growth of Mn doped InAs QDs in GaAs there is hardly any evidence that these Mn doped structures are truly magnetically active and that Mn is incorporated in the structures. Although many characterization techniques have been employed to study these magnetically doped dots the research is severely hampered by the lack of a proper technique to visualize the incorporation of Mn in InAs QDs.…”

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Atomic scale characterization of Mn doped InAs/GaAs quantum dots

Bozkurt

Grant

Ulloa

et al. 2010

Applied Physics Letters

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Several growth procedures for doping InAs/GaAs quantum dots ͑QDs͒ with manganese ͑Mn͒ have been investigated with cross-sectional scanning tunneling microscopy. It is found that expulsion of Mn out of the QDs and subsequent segregation makes it difficult to incorporate Mn in the QDs even at low growth temperatures of T = 320°C and high Mn fluxes. Mn atoms in and around QDs have been observed with strain and potential confinement changing the appearance of the Mn features.

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Mn-doped InAs self-organized diluted magnetic quantum-dot layers with Curie temperatures above 300K

Cited by 84 publications

References 19 publications

Tailoring Magnetism in Quantum Dots

Tailoring Magnetism in Quantum Dots

Гетероструктуры с квантовыми точками InGaAs/GaAs, легированными атомами переходных элементов. I. Фотолюминесцентные свойства

Atomic scale characterization of Mn doped InAs/GaAs quantum dots

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