13 research outputs found
Strain Redistribution At The Phase Transition Of Mnas/gaas (001) Films
No full textWe investigated the thermal evolution of the lattice parameters of a MnAs film epitaxially grown on GaAs(001) around its magnetostructural first-order phase transition using x-ray diffraction. Despite the substrate constraint, large variation of one of the in-plane lattice parameters is preserved, typical of bulk MnAs phase transition, during a large temperature range where two phases coexist. We demonstrated that the condition of the constant film length along this direction, in accord to the substrate length, is always fulfilled during the process. The effect is attributed to the gliding of misfit dislocations present on the film. © 2006 American Institute of Physics.8815Žutić, I., Fabian, J., Das Sarma, S., (2004) Rev. Mod. Phys., 76, p. 323Ramsteiner, M., Hao, H.Y., Kawaharazuka, A., Zhu, H.J., Kastner, M., Hey, R., Däweritz, L., Ploog, K.H., (2002) Phys. Rev. B, 66, p. 081304Tanaka, M., Harbinson, J.P., Sands, T., Cheeks, T.L., Keramidas, V.G., Rothberg, G.M., (1994) J. Vac. Sci. Technol. B, 12, p. 1091Tanaka, M., Harbinson, J.P., (1994) Appl. Phys. Lett., 65, p. 1964Plake, T., Ramsteiner, M., Kaganer, V.M., Jenichen, B., Kästner, M., Däweritz, L., Ploog, K.H., (2002) Appl. Phys. Lett., 80, p. 2523Kaganer, V.M., Jenichen, B., Schippan, F., Braun, W., Däweritz, L., Ploog, K.H., (2000) Phys. Rev. Lett., 85, p. 341Iikawa, F., Brasil, M.J.S.P., Couto, O.D.D., Adriano, C., Giles, C., Däweritz, L., (2004) Appl. Phys. Lett., 85, p. 2250Song, J.H., Cui, Y., Lee, J.J., Ketterson, J.B., (2005) Appl. Phys. Lett., 87, p. 092504Däweritz, L., Herrmann, C., Mohanty, J., Hesjedal, T., Ploog, K.H., Bauer, E., Locatelli, A., Heun, S., (2005) J. Vac. Sci. Technol. B, 23, p. 1759Iikawa, F., Brasil, M.J.S.P., Adriano, C., Couto, O.D.D., Giles, C., Santos, P.V., Däweritz, L., Sanvito, S., (2005) Phys. Rev. Lett., 95, p. 077203Kaganer, V.M., Jenichen, B., Schippan, F., Braun, W., Däweritz, L., Ploog, K.H., (2002) Phys. Rev. B, 66, p. 045305Schippan, F., Trampert, A., Däweritz, L., Ploog, K.H., (1999) J. Vac. Sci. Technol. B, 17, p. 1716Giles, C., Yokaichia, F., Kycia, S.W., Sampaio, L.C., Ardiles-Saraiva, D.C., Franco, M.K.K., Neuenschwander, R.T., (2003) J. Synchrotron Radiat., 10, p. 430Kästner, M., Herrmann, C., Däweritz, L., Ploog, K.H., (2002) J. Appl. Phys., 92, p. 5711Iikawa, F., Santos, P.V., Kästner, M., Schippan, F., Däweritz, L., (2002) Phys. Rev. B, 65, p. 20532
Evidence For Photon Anti-bunching In Acoustically Pumped Dots
No full textWe demonstrate the controlled transfer of photoexcited carriers by a surface acoustic wave (SAW) between coupled quantum wells, wires, and dots grown on a semiconductor surface. The quantum wires and dots used in the experiments are embedded at photolithographically defined positions within an (Al,Ga)As/GaAs (311)A-oriented quantum well grown by molecular beam epitaxy. We give experimental evidence for the anti-bunching of photons emitted in a quantum dot pumped by electrons and holes transported from the quantum well by a surface acoustic wave. © 2009 Elsevier B.V. All rights reserved.421024972500Sogawa, T., Santos, P.V., Zhang, S.K., Eshlaghi, S., Wieck, A.D., Ploog, K.H., (2001) Phys. Rev. Lett., 87, pp. 276601-1Stotz, J.A.H., Hey, R., Santos, P.V., Ploog, K.H., (2005) Nat. Mater., 4, p. 585Couto Jr., O.D.D., Iikawa, F., Rudolph, J., Hey, R., Santos, P.V., (2007) Phys. Rev. Lett., 98, p. 036603Wiele, C., Haake, F., Rocke, C., Wixforth, A., (1998) Phys. Rev. A, 58, p. 2680Foden, C.L., Talyanskii, V.I., Milburn, G.J., Leadbeater, M.L., Pepper, M., (2000) Phys. Rev. A, 62, pp. 011803RHosey, T., Talyanskii, V., Vijendran, S., Jones, G.A.C., Ward, M.B., Unitt, D.C., Norman, C.E., Shields, A.J., (2004) Appl. Phys. Lett., 85, p. 491Bdefeld, C., Ebbecke, J., Toivonen, J., Sopanen, M., Lipsanen, H., Wixforth, A., (2006) Phys. Rev. B, 74 (3), p. 035407Ntzel, R., Menniger, J., Ramsteiner, M., Ruiz, A., Schnherr, H.-P., Ploog, K.H., (1996) Appl. Phys. Lett., 68, p. 1132De Lima Jr., M.M., Santos, P.V., (2005) Rep. Prog. Phys., 68, p. 1639Couto Jr., O.D.D., (2009) Nat. Photonics, 3, p. 64
Acoustically-driven Single Photon Sources On (311)a Gaas
No full textWe employ surface acoustic waves to control the transfer of photo-generated carriers between interconnected quantum wells and wires grown on pre-patterned (311)A GaAs substrates. The wires are embedded at photo-lithographically defined positions within (Al,Ga)As/GaAs quantum well. Optical studies on these structures have shown sharp PL lines and antibunched photons with tunable emission energy, revealing the presence of several recombination centers within the wire. The spatial separation of these recombination centers emitting single photons is determined from time-resolved measurements. © 2011 American Institute of Physics.139910351036Int. Union Pure Appl. Phys. (IUPAP C8 Comm.),Korean Ministry of Education, Science and Technology,Seoul Metropolitan Government,Office of Naval Research Global,Korea Tourism OrganizationRocke, C., (1997) Phys. Rev. Lett., 78, p. 4099Notzel, (1996) Appl. Phys. Lett., 68, p. 1132Hey, R., (2004) Physica E, 21, p. 737Couto, O.D.D., (2009) Nat. Photonics, 3, p. 645Intonti, (2001) Phys. Rev. B, 63, p. 07531
Identification of low-temperature photoluminescence peaks by laser treatment in van der Waals epitaxially grown WS2 monolayers
No full textSpin-orbit Dependence On Carrier Momentum In (1 1 0) Gaas Quantum Wells
No full textSurface acoustic waves (SAW) are employed to transport optically generated spin ensembles over distances exceeding 60 μ m in (1 1 0) GaAs quantum wells (QW). The dependence of the spin-orbit (SO) coupling on carrier momentum is investigated by using SAWs to transport spins with well-defined velocity along different directions in the QW plane. For transport along the [0 0 1] direction, the high relaxation rates for the in-plane spin component lead to fast spin decoherence under a magnetic field. For the [over(1, -) 1 0] direction, in contrast, a non-zero average value of the SO internal magnetic field retards the longitudinal spin relaxation. © 2007 Elsevier B.V. All rights reserved.40617971799Zutić, I., Fabian, J., Das Sarma, S., (2004) Rev. Mod. Phys., 76, p. 323Sogawa, T., (2001) Phys. Rev. Lett., 87, p. 276601Dyakonov, M.I., Kochorovskii, V.Y.Yu., (1986) Sov. Phys. Semicond., 20, p. 110Eppenga, R., Schuurmans, M.F.H., (1988) Phys. Rev. B, 37, p. 10923Ohno, Y., (1999) Phys. Rev. Lett., 83, p. 4196Döhrmann, S., (2004) Phys. Rev. Lett., 93, p. 147405Couto Jr., O.D.D., (2007) Phys. Rev. Lett., 98, p. 036603de Lima Jr., M.M., (2003) J. Appl. Phys., 94, p. 784
Revealing the nature of low-temperature photoluminescence peaks by laser treatment in Van der Waals epitaxially grown WS2 monolayers
No full textMonolayers of transition metal dichalcogenides (TMD) are promising materials for optoelectronics devices. However, one of the challenges is to fabricate large-scale growth of high quality TMD monolayers with the desired properties in order to expand their use in potential applications. Here, we demonstrate large-scale tungsten disulfide (WS2) monolayers grown by van der Waals Epitaxy (VdWE). We show that, in addition to the large structural uniformity and homogeneity of these samples, their optical properties are very sensitive to laser irradiation. We observe a time instability in the photoluminescence (PL) emission at low temperatures in the scale of seconds to minutes. Interestingly, this change of the PL spectra with time, which is due to laser induced carrier doping, is employed to successfully distinguish the emission of two negatively charged bright excitons. Furthermore, we also detect blinking sharp bound exciton emissions which are usually attractive for single photon sources. Our findings contribute to a deeper understanding of this complex carrier dynamics induced by laser irradiation which is very important for future optoelectronic devices based on large scale TMD monolayers
Photon Anti-bunching In Acoustically Pumped Quantum Dots
No full textAlthough extensive research on nanostructures has led to the discovery of a number of efficient ways to confine carriers in reduced dimensions, little has been done to make use of the unique properties of various nanostructured systems through coupling by means of the controllable transfer of carriers between them. Here, we demonstrate a novel approach for the controllable transfer of electrons and holes between a semiconductor quantum well and an embedded quantum dot using the moving piezoelectric potential modulation induced by an acoustic phonon. We show that this moving potential not only transfers carriers between the quantum well and an array of quantum dots, but can also control their capture and recombination in discrete quantum dot states within the array. This feature is used to demonstrate a high-frequency, single-photon source with tunable emission energy by acoustically transferring carriers to a selected quantum dot. © 2009 Macmillan Publishers Limited.311645648Shilton, J.M., High-frequency single-electron transport in a quasi-onedimensional GaAs channel induced by surface acoustic waves (1996) J. Phys. Condens. Matter, 8, pp. L531-L539Rocke, C., Acoustically driven storage of light in a quantum well (1997) Phys. Rev. Lett., 78, pp. 4099-4102Sogawa, T., Transport and lifetime enhancement of photoexcited spins in GaAs by surface acoustic waves (2001) Phys. Rev. Lett., 87, p. 276601Rudolph, J., Hey, R., Santos, P.V., Long-range exciton transport by dynamic strain fields in a GaAs quantum well (2007) Phys. Rev. Lett., 99, p. 047602Imamoglu, A., Yamamoto, Y., Nonclassical light generation by Coulomb blockade of resonant tunneling (1992) Phys. Rev. B, 46, p. 015982Wiele, C., Photon trains and lasing: The periodically pumped quantum dot (1998) Phys. Rev. A, 58, pp. R2680-R2683Foden, C.L., High-frequency acousto-electric single-photon source (2000) Phys. Rev. A, 62, p. 011803Stotz, J.A.H., Hey, R., Santos, P.V., Ploog, K.H., Coherent spin transport via dynamic quantum dots (2005) Nature Mater., 4, pp. 585-588Couto Jr, O.D.D., Iikawa, F., Rudolph, J., Hey, R., Santos, P.V., Anisotropic spin transport in(110) GaAs quantum wells (2007) Phys. Rev. Lett., 98, p. 036603Lounis, B., Orrit, M., Single-photon sources (2005) Rep. Prog. Phys., 68, pp. 1129-1179Hosey, T., Lateral n-p junction for acoustoelectric nanocircuits (2004) Appl. Phys. Lett., 85, pp. 491-493Bodefeld, C., Experimental investigation towards a periodically pumped single-photon source (2006) Phys. Rev. B, 74, p. 035407Notzel, R., Selectivity of growth on patterned GaAs(311)A substrates (1996) Appl. Phys. Lett., 68, pp. 1132-1134Hey, R., Conductance anisotropy of high-mobility two-dimensional hole gas at GaAs/(Al,Ga)As(1 1 3)A single heterojunctions (2004) Physica e, 21, pp. 737-741Intonti, F., Near-field optical spectroscopy of localized and delocalized excitons in a single GaAs quantum wire (2001) Phys. Rev. B, 63, p. 075313Sogawa, T., Dynamic band-structure modulation of quantum wells by surface acoustic waves (2001) Phys. Rev. B, 63, p. 121307De Lima Jr, M.M., Santos, P.V., Modulation of photonic structures by surface acoustic waves (2005) Rep. Prog. Phys., 68, pp. 1639-1701Hanbury-Brown, R., Twiss, R.Q., (1956) Nature, 177, pp. 27-29Bennett, A.J., Electrical control of the uncertainty in the time of single photon emission events (2005) Phys. Rev. B, 72, p. 03331
Coherent Spin Transport By Acoustic Fields In Gaas Quantum Wells
No full textWe review processes for long-range spin transport and manipulation in GaAs quantum wells using mobile potentials created by the piezoelectric field of a surface acoustic wave. By reducing spin dephasing mechanisms associated with the spin orbit-coupling, these potentials can coherently transport spins over distances on the order of 100 μm. © 2006 WILEY-VCH Verlag GmbH & Co. KGaA.31243074312Prinz, G.A., (1995) Phys. Today, 48, p. 58Smet, J.H., (2002) Nature, 415, p. 281Zrenner, A., (2002) Nature, 418, p. 612Datta, S., Das, B., (1990) Appl. Phys. Lett, 56, p. 665Stotz, J.A.H., Hey, R., Santos, P.V., Ploog, K.H., (2005) Nature Mater, 4, p. 584Santos, P.V., Stotz, J.A.H., Hey, R., (2005) Realizing controllable quantum states: Proc. of the Int. Symp. on Mesoscopic Superconductivity and Spintronics - In the light of quantum computation, p. 357. , edited by H. Takayanagi and J. Nitta World Scientific, SingaporeSogawa, T., (2001) Phys. Rev. Lett, 87, p. 276601Rocke, C., (1997) Phys. Rev. Lett, 78, p. 4099Barnes, C.H.W., Shilton, J.M., Robinson, A.M., (2000) Phys. Rev. B, 62, p. 8410Alsina, F., Stotz, J.A.H., Hey, R., Santos, P.V., (2004) Solid State Commun, 129, p. 453Ohno, Y., (1999) Phys. Rev. Lett, 83, p. 4196D'yakonov, M.I., Perel', V.I., (1972) Sov. Phys. Solid State, 13, p. 3023Dyakonov, M.I., Kachorovskii, V.Y.Y., (1986) Sov. Phys. Semicond, 20, p. 110Stotz, J.A.H., Hey, R., Santos, P.V., (2005) Mater. Sci. Eng. B, 126, p. 164Kikkawa, J.M., Awschalom, D.D., (1999) Nature, 397, p. 139Stotz, J.A.H., Santos, P.V., Hey, R., Ploog, K.H., unpublishedGovorov, A.O., (2001) Phys. Rev. Lett, 87, p. 226803Adachi, T., Ohno, Y., Matsukura, F., Ohno, H., (2001) Physica E, 10, p. 36Karimov, O.Z., (2003) Phys. Rev. Lett, 91, p. 246601Döhrmann, S., (2004) Phys. Rev. Lett, 93, p. 147405Hall, K.C., (2004) Phys. Rev. B, 68, p. 11531
Long-range Spin Transport In (110) Gaas Quantum Wells
No full textWe report on long-range (>60 μm) coherent spin transport via surface acoustic waves in (110) GaAs quantum wells. The long transport distances, attributed to the quenching of the exciton exchange interaction and to the inhibition of the D'yakonov PereP spin relaxation mechanism, allow the manipulation of the electron spin during the acoustic transport via external magnetic fields. Potential applications include for quantum information processing. © 2007 American Institute of Physics.89312731274Datta, S., Das, B., (1990) Appl. Phys. Lett., 56, pp. 665-667Zutić, I., Fabian, J., Das Sarma, S., (2004) Rev. Mod. Phys., 76, pp. 323-410Sogawa, T., Santos, P.V., Zhang, S.K., Eshlaghi, S., Wieck, A.D., Ploog, K.H., (2001) Phys. Rev. Lett., 87, p. 276601Furuta, S., Barnes, C.H.W., Doran, C.J.L., (2004) Phys. Rev. B, 70, p. 205320D'yakonov, M.I., Perel, V.I., (1971) Sov. Phys. JETP, 33, pp. 1053-1059D'yakonov, M.I., Kachorovskii, V.Y.Y., (1986) Sov. Phys. Semicond., 20, pp. 110-112De Lima Jr., M.M., Alsina, F., Seidel, W., Santos, P.V., (2003) J. Appl. Phys., 94, pp. 7848-7855Kikkawa, J.M., Awschalom, D.D., (1998) Phys. Rev. Lett., 80, p. 4313Stotz, J.A.H., Hey, R., Santos, P.V., Ploog, K.H., (2005) Nat. Mat., 4, pp. 585-588Ohno, Y., Terauchi, R., Adachi, T., Matsukura, F., Ohno, H., (1999) Phys. Rev. Lett., 83, p. 4196Bir, G.L., Aronov, A.G., Pikus, G.E., (1976) Sov. Phys. JETP, 42, pp. 705-712Döhrmann, S., Hägele, D., Rudolph, J., Schuh, D., Bichler, M., Oestreich, M., (2004) Phys. Rev. Lett., 93, p. 14740
Apparent Split Between Magnetic And Structural Phase Transitions In Epitaxial Mnas Films
No full textWe investigate the magnetic field dependence of the magnetic and structural phase transition of an epitaxial MnAs layer grown on GaAs (100) by using SQUID magnetometry and X-ray diffraction. The phase transition temperatures obtained from magnetic and structural results revealed an apparent splitting for magnetic field less than ∼1kOe, while for higher magnetic fields a behavior similar to that reported for bulk MnAs is observed. © 2004 Elsevier B.V. All rights reserved.272-27611541156Schippan, F., Trampert, A., Däweritz, L., Ploog, K.H., (1999) J. Vac. Sci. Technol., B17, p. 1716Trampert, A., Schippan, F., Däweritz, L., Ploog, K.H., (2001) Appl. Phys. Lett., 78, p. 2461Kaganer, V.M., Jenichen, B., Schippan, F., Braun, W., Däweritz, L., Ploog, K.H., (2000) Phys. Rev. Lett., 85, p. 341Iikawa, F., Santos, P.V., Kästner, M., Schippan, F., Däweritz, L., (2002) Phys. Rev. B, 65, p. 205328Zieba, A., Shapira, Y., Foner, S., (1982) Phys. Lett., 91 A, p. 243Chernenko, V.A., Wee, L., McCormick, P.G., Street, R., (1999) J. Appl. Phys., 85, p. 7833Plake, T., Ramsteiner, M., Kaganer, V.M., Jenichen, B., Kästner, M., Däweritz, L., Ploog, K.H., (2002) Appl. Phys. Lett., 80, p. 252
