Polarized and resonant Raman spectroscopy on single InAs nanowires

We report polarized Raman scattering and resonant Raman scattering studies on single InAs nanowires.Polarized Raman experiments show that the highest scattering intensity is obtained when both the incident and analyzed light polarizations are perpendicular to the nanowire axis. InAs wurtzite optical modes are observed. The obtained wurtzite modes are consistent with the selection rules and also with the results of calculations using an extended rigid-ion model. Additional resonant Raman scattering experiments reveal a redshifted E1 transition for InAs nanowires compared to the bulk zinc-blende InAs transition due to the dominance of the wurtzite phase in the nanowires. Ab initio calculations of the electronic band structure for wurtzite and zinc-blende InAs phases corroborate the observed values for the E1 transitions

Exciton G Factor Of Type-ii Inp Gaas Single Quantum Dots

We investigated the magneto-optical properties of type-II InP GaAs quantum dots using single-dot spectroscopy. The emission energy from individual dots presents a quadratic diamagnetic shift and a linear Zeeman splitting as a function of magnetic fields up to 10 T, as previously observed for type-I systems. We analyzed the in-plane localization of the carriers using the diamagnetic shift results. The values for the exciton g factor obtained for a large number of a InP GaAs dots are mainly constant, independent of the emission energy, and therefore, of the quantum dot dimensions. The result is attributed to the weak confinement of the holes in type-II InP GaAs quantum dots. © 2006 The American Physical Society.733Toda, Y., Shinomori, S., Suzuki, K., Arakawa, Y., (1998) Appl. Phys. Lett., 73, p. 517. , APPLAB 0003-6951 10.1063/1.121919Bayer, M., Kuther, A., Schäfer, F., Reithmaier, J.P., Forchel, A., (1999) Phys. Rev. B, 60, p. 8481. , PRBMDO. 0163-1829. 10.1103/PhysRevB.60.R8481Sugisaki, M., Ren, H.-W., Nishi, K., Sugou, S., Okuno, T., Masumoto, Y., (1998) Physica B, 256-258, p. 169. , PHYBE3 0921-4526Kotlyar, R., Reinecke, T.L., Bayer, M., Forchel, A., (2001) Phys. Rev. B, 63, p. 085310. , PRBMDO 0163-1829 10.1103/PhysRevB.63.085310Ribeiro, E., Govorov, A.O., Carvalho Jr., W., Medeiros-Ribeiro, G., (2004) Phys. Rev. Lett., 92, p. 126402. , PRLTAO 0031-9007 10.1103/PhysRevLett.92.126402Janssens, K.L., Partoens, B., Peeters, F.M., (2002) Phys. Rev. B, 66, p. 075314. , PRBMDO 0163-1829 10.1103/PhysRevB.66.075314Kalameitsev, A.B., Kovalev, V.M., Govorov, A.O., (1989) JETP Lett., 68, p. 669. , JTPLA2 0021-3640 10.1134/1.567926Sugisaki, M., Ren, H.W., Nair, S.V., Nishi, K., Masumoto, Y., (2002) Phys. Rev. B, 66, p. 235309. , PRBMDO 0163-1829 10.1103/PhysRevB.66.235309Godoy, M.P.F., Nakaema, M.K.K., Iikawa, F., Carvalho Jr., W., Ribeiro, E., Gobby, A.L., (2004) Rev. Sci. Instrum., 75, p. 1947. , RSINAK 0034-6748 10.1063/1.1753090Walck, S.N., Reinecke, T.L., (1998) Phys. Rev. B, 57, p. 9088. , PRBMDO 0163-1829 10.1103/PhysRevB.57.9088Laheld, U.E.H., Pedersen, F.B., Hemmer, P.C., (1993) Phys. Rev. B, 48, p. 4659. , PRBMDO 0163-1829 10.1103/PhysRevB.48.4659Bastard, G., Mendez, E.E., Chang, L.L., Esaki, L., (1982) Phys. Rev. B, 26, p. 1974. , PRBMDO 0163-1829 10.1103/PhysRevB.26.1974Nakaoka, T., Saito, T., Tatebayashi, J., Arakawa, Y., (2004) Phys. Rev. B, 70, p. 235337. , PRBMDO 0163-1829 10.1103/PhysRevB.70.235337Yugova, I.A., Ya. Gerlovin, I., Davydov, V.G., Ignatiev, I.V., Kozin, I.E., Ren, H.W., Sugisaki, M., Masumoto, Y., (2002) Phys. Rev. B, 66, p. 235309. , PRBMDO 0163-1829 10.1103/PhysRevB.66.235309Willmann, F., Suga, S., Dreybrodt, W., Cho, K., (1974) Solid State Commun., 14, p. 783. , SSCOA4 0038-1098Landi, S.M., Tribuzy, C.V.B., Souza, P.L., Butendeich, R., Bittencourt, A.C., Marques, G.E., (2003) Phys. Rev. B, 67, p. 085304. , PRBMDO 0163-1829 10.1103/PhysRevB.67.08530

Carrier Dynamics In Stacked Inpgaas Quantum Dots

We investigated two stacked layers of InPGaAs type-II quantum dots by transmission electron microscopy and optical spectroscopy. The results reveal that InP quantum dots formed in two quantum dot layers are more uniform than those from a single layer structure. The thermal activation energies as well as the photoluminescence decays are rather independent of the separation between quantum dot layers and the presence of the second layer. The quantum dot optical emission persists for thermal activation energy larger than the calculated exciton binding energy. The photoluminescence decay is relatively fast for type-II alignment. © 2007 American Institute of Physics.9112Goldstein, L., Glas, F., Marzin, M.J.Y., Charasse, N., Le Roux, G., (1985) Appl. Phys. Lett., 47, p. 1099Xie, Q., Madhkar, A., Chen, P., Kobayashi, N., (1995) Phys. Rev. Lett., 75, p. 2542Ledentsov, N.N., Shchukin, V.A., Grundmann, M., Kirstaedter, N., Böhmer, J., Schmidt, O., Bimberg, D., Heydenreich, J., (1996) Phys. Rev. B, 54, p. 8743Solomon, G.S., Trezza, J.A., Marchall, A.F., Harris Jr., J.S., (1996) Phys. Rev. Lett., 76, p. 952Sugiyama, Y., Nakata, Y., Futatsugi, T., Sugawara, M., Awano, Y., Yokoyama, N., (1996) Jpn. J. Appl. Phys., Part 2, 36, p. 158Schmidt, O.G., Kienzie, O., Hao, Y., Eberl, K., (1999) Appl. Phys. Lett., 74, p. 1272Chang, W.-H., Chen, W.-Y., Chou, A.-T., Hsu, T.-M., Chen, P.-S., Pei, Z., Lai, L.-S., (2003) J. Appl. Phys., 93, p. 4999Susuki, K., Hogg, R.A., Arakawa, Y., (1999) J. Appl. Phys., 85, p. 8349Sun, C.-K., Wang, G., Bowers, J.E., Brar, B., Blank, H.-R., Kroemer, H., Pilkuhn, M.H., (1996) Appl. Phys. Lett., 68, p. 1543Hatami, F., Grundmann, M., Ledentsov, N.N., Heinrichsdorff, F., Heitz, R., Böhrer, J., Bimberg, D., Alferov Zh., I., (1998) Phys. Rev. B, 57, p. 4635De Godoy, M.P.F., Gomes, P.F., Nakaema, M.K.K., Iikawa, F., Brasil, M.J.S.P., Caetano, R.A., Madureira, J.R., Bittencourt, A.C.R., (2006) Phys. Rev. B, 73, p. 033309Wang, B., Chua, S.-J., (2001) Appl. Phys. Lett., 78, p. 628Nakaema, M.K.K., Iikawa, F., Brasil, M.J.S.P., Ribeiro, E., Medeiros-Ribeiro, G., Carvalho Jr., W., Maialle, M.Z., Degani, M.H., (2002) Appl. Phys. Lett., 81, p. 2743Zundel, M.K., Specht, P., Eberl, K., Jin-Phillipp, N.Y., Phillipp, F., (1997) Appl. Phys. Lett., 71, p. 2972Sanguinetti, S., Henini, M., Grassi Alessi, M., Capizzi, M., Frigeri, P., Franchi, S., (1999) Phys. Rev. B, 60, p. 827

Rabi-split States Broadened By A Continuum

In this work we theoretically investigate a Λ-like three-level system. Our model consists of a onedimensional quantum well with a nearby continuum. The Λ level structure is formed by the ground state (a valence band state) and two excited states (both in conduction band), one being a localized and the other a quasi-bound state which is interacting with the continuum. An infrared (IR) field is used to drive the excited states into dressed states creating Autler-Townes doublets. We solve the semiconductor Bloch equation, in real space and in time domain, to follow the interband optical excitation dynamics. The optical absorption and the photocurrent spectra are calculated for different potential barriers separating the well and the continuum. We show how this affects the Autler-Townes doublets since this is a possible way of changing the relationship between the IR Rabi frequency and the dephasing rates. © 2013 AIP Publishing LLC.1566500501et al.,ETH Board,ETH Zurich,International Union of Pure and Applied Physics,Swiss National Science Foundation,Swiss Natl. Cent. Competence Res., Quantum Sci. Technol.Publisher: American Institute of Physics Inc.Allen, L., Eberly, J.H., (1975) Optical Resonance and Two Level Atoms, , New York :WileyLevine, B.F., (1993) J. Appl. Phys., 74 (8), pp. R1Müller, K., Reithmaier, G., Clark, E.C., Jovanov, V., Bichler, M., Krenner, H.J., Betz, M., Finley, J.J., (2011) Phys. Rev. B, 84, pp. 081302RAutler, S.H., Townes, C.H., Rev, P., (1955), 100, p. 703Madureira, J.R., Schulz, P.A., Maialle, M.Z., (2004) Phys. Rev. B, 70, p. 033309M. Z. Maialle, M. H. Degani, and J. R. Madureira, unpublishedSadeghi, S.M., Meyer, J., (1997) J. Phys.: Condens. Matter, 9, p. 768

On A Generalized Gibbs-boltzmann Ensemble Formalism For Dissipative Systems

The Nonequilibrium Statistical Operator Method, constructed on the basis of a generalized Gibbs-Boltzmann ensemble formalism, is gaining prominence as an approach to problems in statistical mechanics of nonequilibrium and nonlinear (dissipative) systems. In this paper, we consider the case of a generalized nonequilibrium grand-canonical ensemble. Besides the traditional densities of energy and particle number, this construction requires the introduction of the associated nonconserving dissipative fluxes of all orders. © 1998 Elsevier Science B.V. All rights reserved.2571-4424428Zubarev, D.N., Morosov, V.N., Röpke, G., (1996) Statistical Mechanics of Nonequilibrium Phenomena, Vol. 1: Basic Concepts, Kinetic Theory(1997) Relaxation and Hydrodynamic Processes, 2. , Akademie Verlag, Berlin, respectivelyLuzzi, R., Vasconcellos, A.R., (1990) Fortschr. Phys./Prog. Phys., 38, p. 887Madureira, J.R., Vasconcellos, A.R., Luzzi, R., A nonequilibrium statistical grand-canonical ensemble: Description in terms of flux operators, IFGW-unicamp internal report (1997) J. Chem. Phys., , in pressPeletminskii, S.V., Sokolovskii, A.I., (1974) Math. Theor. Phys. (USSR), 18, p. 121Luzzi, R., Vasconcellos, A.R., (1997) Physica A, 241, p. 667Ramos, J.G., Vasconcellos, A.R., Garcia-Colin, L.S., (1997) Braz. J. Phys., 27, p. 58

Impact Ionization And High-field Effects In Wide-band-gap Semiconductors

Impact ionization is important for electron transport in wide-band-gap semiconductors at high electric fields. We consider a realistic band structure as well as high-field quantum corrections such as the intracollisional field effect in the calculation of the microscopic scattering rate. A pronounced softening of the impact ionization threshold is obtained. This field-dependent impact ionization rate is included within a full-band ensemble Monte Carlo simulation of high-field transport in ZnS. Although the impact ionization rate itself is strongly affected, little effect is observed on measurable quantities such as the impact ionization coefficient. © 2002 Elsevier Science B.V. All rights reserved.3141-45254Ang, W.M., (1995) J. Appl. Phys., 77, p. 2719Reigrotzki, M., Stobbe, M., Redmer, R., Schattke, W., (1995) Phys. Rev. B, 52, p. 1456Reigrotzki, M., (1996) J. Appl. Phys., 80, p. 5054Dür, M., (1998) J. Appl. Phys., 83, p. 3176Reigrotzki, M., (1997) Phys. Stat. Sol. B, 204, p. 528Dür, M., (1999) Physica B, 272, p. 295Quade, W., Schöll, E., Rossi, F., Jacoboni, C., (1994) Phys. Rev. B, 50, p. 7398Redmer, R., (2000) J. Appl. Phys., 87, p. 781Reigrotzki, M., (2001) Int. J. High Speed Electron. Systems, 11, p. 511Reigrotzki, M., (1999) J. Appl. Phys., 86, p. 4458Madureira, J.R., Semkat, D., Bonitz, M., Redmer, R., (2001) J. Appl. Phys., 90, p. 829Bude, J., Hess, K., Iafrate, G.J., (1992) Phys. Rev. B, 45, p. 1095

Exciton Binding Energy In Type Ii Quantum Dots

We investigated the optical properties of self-assembled InP/GaAs quantum dots using continuous-wave and time-resolved photoluminescence spectroscopy. The thermal activation energy, which is directly related to the exciton binding energy in this system, was obtained by photoluminescence measurements as a function of temperature. We obtained thermal activation energies of 6-9 meV for undoped quantum dots and 13 meV for the modulation-doped sample. Those values are in good agreement with calculated results. The dots presented a recombination time of- 0.8-1.1 ns, which is surprisingly small for a type-II system. © 2007 WILEY-VCH Verlag GmbH & Co. KGaA.42385388Huffaker, D.L., Park, G., Zou, Z., Shchekin, O.B., Deppe, D.G., (1998) Appl. Phys. Lett, 73 (18), p. 2564Schedelbeck, G., Wegscheider, W., Bichler, M., Abstreiter, G., (1997) Science, 278, p. 1792Lelong, P., Suzuki, K., Bastard, G., Sakaki, H., Arakawa, Y., (2000) Physica E, 7, p. 393Madureira, J.R., de Godoy, M.P.F., Brasil, M.J.S.P., Iikawa, F., to be publishedde Godoy, M.P.F., Gomes, P.F., Nakaema, M.K.K., Caetano, R.A., Iikawa, F., Brasil, M.J.S.P., Bortoleto, J.R.R., Marques, G.E., (2006) Phys. Rev. B, 73 (3), p. 33309Sanguinetti, S., Henini, M., Alessi, M.G., Capizzi, M., Frigeri, P., Franchi, S., (1999) Phys. Rev. B, 60 (11), p. 8276Fafard, S., Raymond, S., Wang, G., Leon, R., Leonard, D., Charbonneau, S., Merz, J.L., Bowers, J.E., (1996) Surf. Sci, 361-362, p. 778Hatami, F., Grundmann, M., Ledentsov, N.N., Heinrichsdorff, F., Heitz, R., Bohrer, J., Bimberg, D., Alferov, Z.I., (1998) Phys. Rev. B, 57 (8), p. 4635Paillard, M., Marie, X., Vanette, E., Amand, T., Kalevich, V.K., Kovsh, A.R., Zhukov, A.E., Ustinov, V.M., (2000) Appl. Phys. Lett, 76, p. 7

Erratum: Polarized and resonant Raman spectroscopy on single InAs nanowires (vol 84, 085318, 2011)

We found out that the polar pattern for the zinc-blende InAs LO mode displayed in Fig. 2(b) of our original paper represents the backscattering Raman intensities from a (11¯2) top surface and not as stated in the original manuscript from a (110) top surface.In the latter the LO mode is forbidden for all configurations