Parameters of the magnetic polaron state in diluted magnetic semiconductors Cd-Mn-Te with low manganese concentration

Ia, Merkulov; Pozina, Galia; Coquillat, Dominique; Paganotto, N.; Siviniant, J.; Jp, Lascaray; Cibert, J.

doi:10.1103/physrevb.54.5727

Cited by 25 publications

(18 citation statements)

References 12 publications

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“…As the magnetic ordering gets settled in below T C , the photocreated excitons can get polarized by forming complexes with magnetic polaron. [31][32][33] These excitons may lower their energy by forming exciton complexes such as charged EXMP or EXMP complexes that do not allow efficient transfer of energy to Mn states, hence quenching the corresponding PL intensity.…”

Section: Resultsmentioning

confidence: 99%

Suppression of Mn photoluminescence in ferromagnetic state of Mn-doped ZnS nanocrystals

et al. 2009

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Magnetic ordering can tune optical properties of photoluminescent dilute magnetic semiconductors. The results of a magnetic field dependent photoluminescence ͑PL͒ up to 50 T above and below ferromagnetic transition temperature T C in Mn-doped ZnS nanocrystals have been reported here. The PL intensity corresponding to internal transition between states of Mn significantly decreases with application of magnetic field below T C but no such suppression was observed above T C even at 50 T. The zero-field PL intensity also exhibits continuous suppression with decreasing temperature in the ferromagnetic state. The PL intensity profiles could be fitted consistently using a model of magnetic-ordering-induced spin-sensitive energy transfer to Mn states below T C .

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Section: Resultsmentioning

confidence: 99%

Suppression of Mn photoluminescence in ferromagnetic state of Mn-doped ZnS nanocrystals

et al. 2009

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“…Thus, depending on the ratio t f /t r , the transient variation of the recombination energy results in an increase of the PL linewidth in case of time-integrated measurements. Second, statistical fluctuations of the average magnetization inside the localization volume are expected to modify the energy of the recombining electron-hole pairs due to the sp-d exchange interaction [16,17]. As the SQD is being probed repeatedly, this results in a linewidth broadening of optical transitions in DMS SQDs.…”

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confidence: 99%

“…Thus, for small magnetic fields, the degree of polarization r of EMP transitions in DMS structures is determined by temporal statisticial fluctuations of the magnetizatio. A quantitative treatment of this effect leads to a linear relation between r and B [16,19]:…”

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confidence: 99%

Optical Spectroscopy on Single Semimagnetic Quantum Dots ? Probing the Interaction between an Exciton and Its Magnetic Environment

Bacher

Максимов

McDonald

et al. 2001

phys. stat. sol. (b)

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Single diluted magnetic semiconductor (DMS) quantum dots are studied by means of photoluminescence spectroscopy and magnetoluminescence. The sp-d exchange interaction between a single electron-hole pair and roughly 100 Mn spins within the dot is demonstrated to result in (i) a significant enhancement (more than one order of magnitude) of the emission linewidth and (ii) a strongly modified magnetic field dependence of the polarization degree in a single DMS quantum dot as compared to a non-magnetic reference sample.Single quantum dots (SQDs) can be regarded as 'nanolaboratories': Discrete energy levels can be occupied by a well defined number of electrons and/or holes either by electrical or optical injection [1][2][3][4][5]. It has been shown, that on one hand the interaction between particles in the dot, like Coulomb [1-4] or exchange interaction [6,7], and on the other hand the influence of the local environment, like charge carriers trapped in neighboring defect states [8][9][10][11], has to be taken into account in order to describe optical transitions of such 'artificial atoms'. The unique possibility to include magnetic ions like, e.g., Mn in the crystal lattice of II-VI materials, opens a new path to manipulate the environment of charge carriers in a SQD in a well defined manner: Electron-hole pairs are able to interact with the Mn spins via the sp-d exchange interaction [12,13]. In this contribution, we will present optical studies on diluted magnetic semiconductur (DMS) SQDs. The interaction of one single electron-hole pair with its magnetic environment is investigated directly by comparing a semimagnetic Cd 0.93 Mn 0.07 Te/ Cd 0.60 Mg 0.40 Te SQD with its electronically identical, but non-magnetic counterpart Cd 0.93 Mg 0.07 Te/Cd 0.60 Mg 0.40 Te. We mainly concentrate on the impact of the sp-d exchange interaction on the linewidth and the polarisation degree of the emission of DMS SQDs.The samples have been grown with molecular beam epitaxy on CdZnTe substrates, embedding three monolayers of Cd 0.93 Mn 0.07 Te and Cd 0.93 Mg 0.07 Te, respectively, between Cd 0.60 Mg 0.40 Te barriers. Due to spatial fluctuations in well width and/or composi-1

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“…3.4) It allows one to describe the anisotropic spin dynamics of the photoexcited holes [13][14][15][16][17][18][19][20][21] (see Chap. 10), the anisotropic properties of magnetic polarons [17][18][19], (see Chap. 8), and the magnetic anisotropy of the ferromagnetic ordered spin system of the Mn ions in the p-type doped heterostructures GaAsMn [22,23].…”

Section: Exchange Hamiltonian For Heavy and Light Holes At The Bottommentioning

confidence: 99%

Exchange Interaction Between Carriers and Magnetic Ions in Quantum Size Heterostructures

Merkulov

Rodina

2010

Introduction to the Physics of Diluted Magnetic Semiconductors

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A very general theoretical discussion of the values of sp d exchange constants is given starting from symmetry properties of diluted magnetic semiconductors. Complex structure of the valence band is fully taken into account with interacting heavy and light holes as well as spin-orbit split-off states kept in the consideration. The form of the Hamiltonian is derived and shown to be, in a general case, anisotropic. A series of approximations is made that reduces the Hamiltionian to a simple form introduced in Chap. 1. Specific cases of two-dimensional quantum wells and zero-dimensional spherical quantum dots are considered. Finally, the role of sp d interaction in spin relaxation processes is discussed. IntroductionIn semiconductor nano-heterostructures the potential energy, that a charge carrier experiences, changes on the length scale that is comparable to the characteristic wavelength of the carriers. In such a case, the quantum-size effects play a dominant role. The quantum confinement significantly affects the exchange interaction between carriers and localized spins of the magnetic ions. The effective exchange Hamiltonian becomes anisotropic because the presence of interfaces reduces the symmetry. In narrow structures with high potential barriers, the quantum confinement changes the ground state energy of the carriers to such an extent that the changes of the ground energy can be comparable to the band gap energy of a bulk

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Parameters of the magnetic polaron state in diluted magnetic semiconductors Cd-Mn-Te with low manganese concentration

Cited by 25 publications

References 12 publications

Suppression of Mn photoluminescence in ferromagnetic state of Mn-doped ZnS nanocrystals

Suppression of Mn photoluminescence in ferromagnetic state of Mn-doped ZnS nanocrystals

Optical Spectroscopy on Single Semimagnetic Quantum Dots ? Probing the Interaction between an Exciton and Its Magnetic Environment

Exchange Interaction Between Carriers and Magnetic Ions in Quantum Size Heterostructures

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