01661nas a2200229 4500008004100000245005800041210005800099300001600157490000800173520102600181100001401207700001901221700001401240700001301254700001901267700002201286700001501308700001801323700002101341700002001362856004901382 2021 eng d00aPhonon Kinetics of Fructose at the Melting Transition0 aPhonon Kinetics of Fructose at the Melting Transition a12269-122760 v1253 a
Terahertz time domain spectroscopy (THz TDS) is used to measure the melting kinetics of fructose molecular crystals. Combining single-crystal anisotropy measurements with density functional calculations, we assign the phonon frequencies and interrogate how specific phonons behave with melting. While nearly all the low-frequency phonons continuously red-shift with heating and melting, the lowest-energy phonon polarized along the c-axis blue-shifts at the melting temperature, suggesting an initial structural change immediately before melting. We find that the kinetics follow a 3D growth model with large activation energies, consistent with previous differential scanning calorimetry (DSC) measurements. The large activation energies indicate that multiple H-bonds must break collectively for the transition. The results suggest the generality of the kinetics for molecular crystals and that THz TDS with picosecond resolution could be used to measure ultrafast kinetics.
1 aDavie, A.1 aVandrevala, F.1 aDampf, S.1 aDeng, Y.1 aGeorge, D., K.1 aSylvester, E., D.1 aKorter, T.1 aEinarsson, E.1 aBenedict, J., B.1 aMarkelz, A., G. uhttps://markelz.physics.buffalo.edu/node/52000619nas a2200193 4500008004100000245008500041210006900126490000900195100001600204700002200220700001800242700001500260700002400275700001500299700001800314700002400332700002000356856004900376 2019 eng d00aBlue Shift of a Molecular Crystal Phonon at the Solid to Liquid Phase Transition0 aBlue Shift of a Molecular Crystal Phonon at the Solid to Liquid 0 v20191 aDavie, Alex1 aVandrevala, Farah1 aDeng, Yanting1 aGeorge, D.1 aSylvester, Eric, D.1 aKorter, T.1 aEinarsson, E.1 aBenedict, Jason, B.1 aMarkelz, Andrea uhttps://markelz.physics.buffalo.edu/node/27601315nas a2200337 4500008004500000020002200045245009400067210006900161260006300230490001000293520025200303653001500555653001700570653001600587653002600603653004400629653001400673653001900687100001900706700001900725700002000744700001400764700001600778700001500794700001900809700000900828700003000837700003600867700002500903856004900928 2019 Engldsh a978-1-5106-2632-400aTunable Compact Narrow Band THz Sources for Frequency Domain THz Anisotropic Spectroscopy0 aTunable Compact Narrow Band THz Sources for Frequency Domain THz aBaltimore, MDbSpie-Int Soc Optical EngineeringcApr 15-170 v109833 a
We demonstrate frequency domain THz anisotropy signature detection for protein crystal models using newly developed compact tunable narrow band THz sources based on Orientation Patterned Gallium Phosphide for turn-key spectroscopic systems.
10aanisotropy10abiomolecules10afemtosecond10aoptical rectification10aorientation patterned gallium phosphide10aTerahertz10aTHz generation1 aGeorge, D., K.1 aLaFave, T., J.1 aMarkelz, A., G.1 aMcNee, I.1 aTekavec, P.1 aKozlov, V.1 aSchunemann, P.1 aSpie1 aBuffalo, Dept, Phys Buffa1 aInstruments, Eugene, O. R. U. S1 aSyst, P., O. B. Nash uhttps://markelz.physics.buffalo.edu/node/18500708nas a2200229 4500008004500000020001400045245011700059210006900176260000800245300001400253490000800267653001500275100001700290700001700307700001700324700002300341700001600364700001200380700001700392700002000409856004900429 2018 Engldsh a0006-349500aIncrease in Dynamical Collectivity and Directionality of Orange Carotenoid Protein in the Photo-Protective State0 aIncrease in Dynamical Collectivity and Directionality of Orange cFeb a522A-522A0 v11410aBiophysics1 aDeng, Y., T.1 aLuck, C., H.1 aRomo, T., D.1 aGrossfield, A., M.1 aBandara, S.1 aRen, Z.1 aYang, X., J.1 aMarkelz, A., G. uhttps://markelz.physics.buffalo.edu/node/24704125nas a2200841 4500008004500000020001400045245005400059210005000113260000800163300000700171490000700178520199900185653001202184653001502196653002202211653001502233653001602248653002902264653001202293653002702305653001402332653001902346653001402365653000802379653002902387100002002416700002102436700002102457700001902478700002102497700001502518700001602533700001502549700001802564700002102582700002102603700002302624700001602647700002602663700001402689700001702703700002402720700001602744700001302760700002602773700001902799700001402818700002002832700001902852700002002871700002002891700001402911700001902925700001602944700001202960700001802972700001902990700001603009700001403025700002003039700001503059700001403074700001303088700001503101700001403116700001403130700001603144700001503160700001503175700002303190700002103213856004903234 2017 Engldsh a0022-372700aThe 2017 terahertz science and technology roadmap0 a2017 terahertz science and technology roadmap cFeb a490 v503 aScience and technologies based on terahertz frequency electromagnetic radiation (100 GHz-30 THz) have developed rapidly over the last 30 years. For most of the 20th Century, terahertz radiation, then referred to as sub-millimeter wave or far-infrared radiation, was mainly utilized by astronomers and some spectroscopists. Following the development of laser based terahertz time-domain spectroscopy in the 1980s and 1990s the field of THz science and technology expanded rapidly, to the extent that it now touches many areas from fundamental science to 'real world' applications. For example THz radiation is being used to optimize materials for new solar cells, and may also be a key technology for the next generation of airport security scanners. While the field was emerging it was possible to keep track of all new developments, however now the field has grown so much that it is increasingly difficult to follow the diverse range of new discoveries and applications that are appearing. At this point in time, when the field of THz science and technology is moving from an emerging to a more established and interdisciplinary field, it is apt to present a roadmap to help identify the breadth and future directions of the field. The aim of this roadmap is to present a snapshot of the present state of THz science and technology in 2017, and provide an opinion on the challenges and opportunities that the future holds. To be able to achieve this aim, we have invited a group of international experts to write 18 sections that cover most of the key areas of THz science and technology. We hope that The 2017 Roadmap on THz science and technology will prove to be a useful resource by providing a wide ranging introduction to the capabilities of THz radiation for those outside or just entering the field as well as providing perspective and breadth for those who are well established. We also feel that this review should serve as a useful guide for government and funding agencies.
10aex-vivo10ageneration10ametal wave-guides10anear-field10aperformance10aphotoconductive emitters10aPhysics10aquantum-cascade lasers10aradiation10asemiconductors10aTerahertz10athz10atime-domain spectroscopy1 aDhillon, S., S.1 aVitiello, M., S.1 aLinfield, E., H.1 aDavies, A., G.1 aHoffmann, M., C.1 aBooske, J.1 aPaoloni, C.1 aGensch, M.1 aWeightman, P.1 aWilliams, G., P.1 aCastro-Camus, E.1 aCumming, D., R. S.1 aSimoens, F.1 aEscorcia-Carranza, I.1 aGrant, J.1 aLucyszyn, S.1 aKuwata-Gonokami, M.1 aKonishi, K.1 aKoch, M.1 aSchmuttenmaer, C., A.1 aCocker, T., L.1 aHuber, R.1 aMarkelz, A., G.1 aTaylor, Z., D.1 aWallace, V., P.1 aZeitler, J., A.1 aSibik, J.1 aKorter, T., M.1 aEllison, B.1 aRea, S.1 aGoldsmith, P.1 aCooper, K., B.1 aAppleby, R.1 aPardo, D.1 aHuggard, P., G.1 aKrozer, V.1 aShams, H.1 aFice, M.1 aRenaud, C.1 aSeeds, A.1 aStohr, A.1 aNaftaly, M.1 aRidler, N.1 aClarke, R.1 aCunningham, J., E.1 aJohnston, M., B. uhttps://markelz.physics.buffalo.edu/node/22400508nas a2200145 4500008004100000245011600041210006900157260001200226100001300238700001100251700001200262700002000274700001600294856005200310 2017 eng d00aGlobal Picosecond Structural Dynamics of Orange Carotenoid Protein in Photo/Chemical Activated Signaling States0 aGlobal Picosecond Structural Dynamics of Orange Carotenoid Prote c03/20171 aDeng, Y.1 aXu, M.1 aLiu, H.1 aBlankenship, R.1 aMarkelz, A. uhttp://meetings.aps.org/link/BAPS.2017.MAR.S4.200601nas a2200193 4500008004500000020001400045245009300059210006900152260000800221300001400229490000800243653001500251100001700266700001500283700001600298700002400314700002000338856004900358 2017 Engldsh a0006-349500aOrange Carotenoid Protein Picosecond Dynamics Changes with Photo and Chemical Activation0 aOrange Carotenoid Protein Picosecond Dynamics Changes with Photo cFeb a441A-441A0 v11210aBiophysics1 aDeng, Y., T.1 aXu, M., Y.1 aLiu, H., J.1 aBlankenship, R., E.1 aMarkelz, A., G. uhttps://markelz.physics.buffalo.edu/node/25000406nas a2200121 4500008004100000245006500041210006500106100001100171700001400182700002000196700001600216856005200232 2017 eng d00aTemperature dependence of phonons in photosynthesis proteins0 aTemperature dependence of phonons in photosynthesis proteins1 aXu, M.1 aMyles, D.1 aBlankenship, R.1 aMarkelz, A. uhttp://meetings.aps.org/link/BAPS.2017.MAR.S4.302183nas a2200325 4500008004500000020001400045245005900059210005800118260000800176300001000184490000600194520131900200653002801519653001301547653002101560653002401581653001301605653002301618653001101641653001601652653002801668653001301696653001001709100001401719700001901733700001601752700002001768700002001788856004901808 2016 Engldsh a2327-912500aModulated orientation-sensitive terahertz spectroscopy0 aModulated orientationsensitive terahertz spectroscopy cJun aA1-A80 v43 aIntramolecular vibrations of large macromolecules reside in the terahertz range. In particular, protein vibrations are closely spaced in frequency, resulting in a nearly continuous vibrational density of states. This density of vibrations interferes with the identification of specific absorption lines and their subsequent association with specific functional motions. This challenge is compounded with the absorption being dominated by the solvent and local relaxational motions. A strategy for removing the isotropic relaxational loss and isolating specific vibrations is to use aligned samples and polarization-sensitive measurements. Here, we demonstrate a technique to rapidly attain the anisotropic resonant absorbance using terahertz time domain spectroscopy and a spinning sample. The technique, modulated orientation-sensitive terahertz spectroscopy (MOSTS), has a nonzero signal only for anisotropic samples, as demonstrated by a comparison between a silicon wafer and a wire grid polarizer. For sucrose and oxalic acid molecular crystals, the MOSTS response is in agreement with modeled results for the intermolecular vibrations. Further, we demonstrate that, even in the presence of a large relaxational background, MOSTS isolates underlying vibrational resonances. (C) 2016 Chinese Laser Press
10aabsorption-spectroscopy10adynamics10aenzyme catalysis10alow-frequency modes10alysozyme10aneutron-scattering10aOptics10aperspective10apolarization modulation10aproteins10awater1 aSingh, R.1 aGeorge, D., K.1 aBae, C., J.1 aNiessen, K., A.1 aMarkelz, A., G. uhttps://markelz.physics.buffalo.edu/node/24201415nas a2200349 4500008004500000020002200045245004200067210004200109260004900151490000900200520047800209653002300687653001300710653000900723653002300732653002500755653001700780653001200797653002100809653001700830653001400847100001400861700002000875700001900895700001400914700002000928700001300948700002100961700001700982700001700999856004901016 2013 Engldsh a978-0-8194-9392-700aMeasuring phonons in protein crystals0 aMeasuring phonons in protein crystals aBellinghambSpie-Int Soc Optical Engineering0 v86233 aUsing Terahertz near field microscopy we find orientation dependent narrow band absorption features for lysozyme crystals. Here we discuss identification of protein collective modes associated with the observed features. Using normal mode calculations we find good agreement with several of the measured features, suggesting that the modes arise from internal molecular motions and not crystal phonons. Such internal modes have been associated with protein function.
10acorrelated motions10adynamics10amode10amolecular crystals10amolecular vibrations10anormal modes10aphonons10aprotein dynamics10aspectroscopy10aTerahertz1 aAcbas, G.1 aNiessen, K., A.1 aGeorge, D., K.1 aSnell, E.1 aMarkelz, A., G.1 aBetz, M.1 aElezzabi, A., Y.1 aSong, J., J.1 aTsen, K., T. uhttps://markelz.physics.buffalo.edu/node/21800620nas a2200193 4500008004100000020001400041245009400055210006900149300001200218490000600230100002100236700002000257700001500277700002100292700002100313700002000334700002300354856004900377 2013 eng d a2156-342X00aPhotoactive yellow protein terahertz response: hydration, heating and intermediate states0 aPhotoactive yellow protein terahertz response hydration heating a288-2940 v31 aGeorge, Deepu, K1 aKnab, Joseph, R1 aHe, Yunfen1 aKumauchi, Masato1 aBirge, Robert, R1 aHoff, Wouter, D1 aMarkelz, Andrea, G uhttps://markelz.physics.buffalo.edu/node/18400573nas a2200169 4500008004100000020001400041245009500055210006900150300001600219490000800235100001700243700002500260700002300285700002300308700002300331856004900354 2012 eng d a1089-563900aImproved mode assignment for molecular crystals through anisotropic terahertz spectroscopy0 aImproved mode assignment for molecular crystals through anisotro a10359-103640 v1161 aSingh, Rohit1 aGeorge, Deepu, Koshy1 aBenedict, Jason, B1 aKorter, Timothy, M1 aMarkelz, Andrea, G uhttps://markelz.physics.buffalo.edu/node/20201418nas a2200289 4500008004500000020001400045245011000059210006900169260000800238300000600246490000800252520061600260653001100876653001200887100002000899700001800919700001200937700001900949700001900968700001500987700001101002700001401013700002001027700001101047700002101058856004901079 2012 Engldsh a0031-900700aTerahertz Response and Colossal Kerr Rotation from the Surface States of the Topological Insulator Bi2Se30 aTerahertz Response and Colossal Kerr Rotation from the Surface S cFeb a50 v1083 aWe report the THz response of thin films of the topological insulator Bi2Se3. At low frequencies, transport is essentially thickness independent showing the dominant contribution of the surface electrons. Despite their extended exposure to ambient conditions, these surfaces exhibit robust properties including narrow, almost thickness-independent Drude peaks, and an unprecedentedly large polarization rotation of linearly polarized light reflected in an applied magnetic field. This Kerr rotation can be as large as 65 degrees and can be explained by a cyclotron resonance effect of the surface states.
10abi2te310aPhysics1 aAguilar, R., V.1 aStier, A., V.1 aLiu, W.1 aBilbro, L., S.1 aGeorge, D., K.1 aBansal, N.1 aWu, L.1 aCerne, J.1 aMarkelz, A., G.1 aOh, S.1 aArmitage, N., P. uhttps://markelz.physics.buffalo.edu/node/22101467nas a2200349 4500008004500000020001400045245004900059210004900108260000800157300000600165490000700171520058300178653001300761653001200774653002900786653001200815653001700827653001400844653002300858653001700881653001400898100001700912700001800929700001500947700001800962700001800980700001600998700001701014700002001031700001701051856004901068 2008 Engldsh a0003-695100aTerahertz response of quantum point contacts0 aTerahertz response of quantum point contacts cJun a30 v923 aWe measure a clear terahertz response in the low-temperature conductance of a quantum point contact at 1.4 and 2.5 THz. We show that this photoresponse does not arise from a heating effect, but that it is instead excellently described by a classical model of terahertz-induced gate-voltage rectification. This effect is distinct from the rectification mechanisms that have been studied previously, being determined by the phase-dependent interference of the source drain and gate voltage modulations induced by the terahertz field. (C) 2008 American Institute of Physics.
10adetector10adevices10afield-effect transistors10aPhysics10aplasma-waves10aradiation10aresonant detection10asubterahertz10atransport1 aSong, J., W.1 aKabir, N., A.1 aKawano, Y.1 aIshibashi, K.1 aAizin, G., R.1 aMourokh, L.1 aReno, J., L.1 aMarkelz, A., G.1 aBird, J., P. uhttps://markelz.physics.buffalo.edu/node/24301967nas a2200349 4500008004500000020001400045245009200059210006900151260000800220300001400228490000700242520094400249653001501193653002101208653002701229653001201256653002701268653002101295653003401316653002301350653003001373653002601403653002201429653001401451100001301465700001401478700001701492700001701509700002001526700002201546856004901568 2008 Engldsh a0006-349500aTerahertz spectroscopy of bacteriorhodopsin and rhodopsin: Similarities and differences0 aTerahertz spectroscopy of bacteriorhodopsin and rhodopsin Simila cApr a3217-32260 v943 aWe studied the low-frequency terahertz spectroscopy of two photoactive protein systems, rhodopsin and bacteriorhodopsin, as a means to characterize collective low-frequency motions in helical transmembrane proteins. From this work, we found that the nature of the vibrational motions activated by terahertz radiation is surprisingly similar between these two structurally similar proteins. Specifically, at the lowest frequencies probed, the cytoplasmic loop regions of the proteins are highly active; and at the higher terahertz frequencies studied, the extracellular loop regions of the protein systems become vibrationally activated. In the case of bacteriorhodopsin, the calculated terahertz spectra are compared with the experimental terahertz signature. This work illustrates the importance of terahertz spectroscopy to identify vibrational degrees of freedom which correlate to known conformational changes in these proteins.
10aBiophysics10abovine rhodopsin10aconformational-changes10aelastic10afrequency normal-modes10alight activation10amolecular-dynamics simulation10aneutron-scattering10aprotein-coupled receptors10atransmembrane helices10avibrational-modes10awild-type1 aBalu, R.1 aZhang, H.1 aZukowski, E.1 aChen, J., Y.1 aMarkelz, A., G.1 aGregurick, S., K. uhttps://markelz.physics.buffalo.edu/node/22201575nas a2200337 4500008004500000020001400045245011100059210006900170260000800239300000600247490000700253520062400260653002900884653002200913653001200935653001700947653001400964653002300978653001701001100001801018700001301036700001701049700001701066700002001083700001701103700001701120700001601137700001801153700001701171856004901188 2006 Engldsh a0003-695100aTerahertz transmission characteristics of high-mobility GaAs and InAs two-dimensional-electron-gas systems0 aTerahertz transmission characteristics of highmobility GaAs and cSep a30 v893 aFrequency-dependent complex conductivity of high-mobility GaAs and InAs two-dimensional-electron-gas (2DEG) systems is studied by terahertz time domain spectroscopy. Determining the momentum relaxation time from a Drude model, the authors find a lower value than that from dc measurements, particularly at high frequencies/low temperatures. These deviations are consistent with the ratio tau(t)/tau(q,) where tau(q) is the full scattering time. This suggests that small-angle scattering leads to weaker heating of 2DEGs at low temperatures than expected from dc mobilit9y. (c) 2006 American Institute of Physics.
10afield-effect transistors10aphotoconductivity10aPhysics10aplasma-waves10aradiation10aresonant detection10asubterahertz1 aKabir, N., A.1 aYoon, Y.1 aKnab, J., R.1 aChen, J., Y.1 aMarkelz, A., G.1 aReno, J., L.1 aSadofyev, Y.1 aJohnson, S.1 aZhang, Y., H.1 aBird, J., P. uhttps://markelz.physics.buffalo.edu/node/22901843nas a2200193 4500008004100000245010000041210006900141260001900210300001900229490000800248520123500256100001601491700001701507700001401524700002401538700001801562700002001580856004901600 2004 eng d00aTerahertz measurements of the Photoactive Protein Bacteriorhodopsin mutant D96N: M and P states0 aTerahertz measurements of the Photoactive Protein Bacteriorhodop aWarrendale, PA apages261–2670 v8263 aWe use terahertz (THz) spectroscopy as a biomaterials characterization tool. Previously we have shown a strong contrast between the THz dielectric response for wild type (WT) and D96N mutant of bacteriorhodopsin. In those studies we observed a large increase in the THz absorbance of WT with excitation to thermally captured photo-intermediates whereas no such increase in absorbance was observed for the mutant D96N. These results suggest that the THz response is sensitive to structural changes and relative flexibility of biomolecules. However the photo-intermediate populations of the WT and D96N samples were not equivalent in those measurements. While the WT samples had relaxed (bR), M and P state intermediates present, the D96N samples had only bR and M states. Here we present terahertz absorbance measurements of D96N as a function of M and P state populations at room temperature. The THz response is constant for intermediate states populations up to 23% M state and up to 30% P state. These results verify that there is a fundamental difference in the conformational dynamics as measured by THz dielectric response for a single residue mutation.
Far infrared ( FIR) spectral measurements of wild-type (WT) and D96N mutant bacteriorhodopsin thin films have been carried out using terahertz time domain spectroscopy as a function of hydration, temperature, and conformational state. The results are compared to calculated spectra generated via normal mode analyses using CHARMM. We find that the FIR absorbance is slowly increasing with frequency and without strong narrow features over the range of 2-60 cm(-1) and up to a resolution of 0.17 cm(-1). The broad absorption shifts in frequency with decreasing temperature as expected with a strongly anharmonic potential and in agreement with neutron inelastic scattering results. Decreasing hydration shifts the absorption to higher frequencies, possibly resulting from decreased coupling mediated by the interior water molecules. Ground-state FIR absorbances have nearly identical frequency dependence, with the mutant having less optical density than the WT. In the M state, the FIR absorbance of the WT increases whereas there is no change for D96N. These results represent the first measurement of FIR absorbance change as a function of conformational state.
10aangstrom resolution10aBiophysics10adna10afilms10afrequency10aharmonic-analysis10ainelastic neutron-scattering10alarge systems10amixed basis10anormal-modes10apurple membranes10astructural-changes10atransform infrared-spectroscopy1 aWhitmire, S., E.1 aWolpert, D.1 aMarkelz, A., G.1 aHillebrecht, J., R.1 aGalan, J.1 aBirge, R., R. uhttps://markelz.physics.buffalo.edu/node/27300445nas a2200145 4500008004100000245005300041210005300094260002200147100001600169700001200185700001900197700001400216700002000230856004900250 2003 eng d00aTerahertz Biosensors based on Xerogel Substrates0 aTerahertz Biosensors based on Xerogel Substrates aSanta Barbara, CA1 aChen, J.-Y.1 aCox, W.1 aBright, F., V.1 aCerne, J.1 aMarkelz, A., G. uhttps://markelz.physics.buffalo.edu/node/31400511nas a2200157 4500008004100000245005900041210005900100260003400159300001200193100001600205700002100221700002000242700002400262700001800286856004900304 2003 eng d00aUltrafast THz spectroscopy of photoactive biomolecules0 aUltrafast THz spectroscopy of photoactive biomolecules aSan Jose, Californiac01/2003 a146-1531 aChen, J.-Y.1 aWhitmire, S., E.1 aMarkelz, A., G.1 aHillebrecht, J., R.1 aBirge, R., R. uhttps://markelz.physics.buffalo.edu/node/31500496nas a2200157 4500008004100000020001400041245007000055210006900125300000900194490000700203100002000210700002000230700002100250700001800271856004900289 2002 eng d a0031-915500aTHz time domain spectroscopy of biomolecular conformational modes0 aTHz time domain spectroscopy of biomolecular conformational mode a37970 v471 aMarkelz, Andrea1 aWhitmire, Scott1 aHillebrecht, Jay1 aBirge, Robert uhttps://markelz.physics.buffalo.edu/node/19400514nas a2200145 4500008004100000245008800041210006900129260003000198300001200228100001700240700002000257700002400277700001800301856004900319 2001 eng d00aTerahertz Time domain spectroscopy of the M intermediate state of Bacteriorhodopsin0 aTerahertz Time domain spectroscopy of the M intermediate state o aToulouse, Francec09/2001 a345-3481 aWhitmire, S.1 aMarkelz, A., G.1 aHillebrecht, J., R.1 aBirge, R., R. uhttps://markelz.physics.buffalo.edu/node/31601364nas a2200253 4500008004500000020001400045245008300059210006900142260000800211300001400219490000700233520064600240653001100886653002800897653002800925653001200953653001500965653001200980100002000992700001801012700001301030700001801043856004901061 1996 Engldsh a0003-695100aInterband impact ionization by terahertz illumination of InAs heterostructures0 aInterband impact ionization by terahertz illumination of InAs he cDec a3975-39770 v693 aExperimental studies of InAs heterostructures illuminated by far-infrared (FIR) radiation reveal an abrupt increase in the charge density for FIR intensities above a threshold value that rises with increasing frequency. We attribute this charge density rise to interband impact ionization in a regime in which omega tau(m) similar to 1, where tau(m) is the momentum relaxation time, and f=omega/2 pi is the FIR frequency. The dependence of the density rise on the FIR field strength supports this interpretation, and gives threshold fields of 3.7-8.9 kV/cm for the frequency range 0.3-0.66 THz. (C) 1996 American Institute of Physics.
10aenergy10afar-infrared excitation10ainas/alsb quantum-wells10ainplane10amodulation10aPhysics1 aMarkelz, A., G.1 aAsmar, N., G.1 aBrar, B.1 aGwinn, E., G. uhttps://markelz.physics.buffalo.edu/node/26600605nas a2200169 4500008004100000245009100041210006900132260003100201300001200232490005000244100001800294700002000312700002000332700001800352700001400370856005100384 1996 eng d00aThird Harmonic Generation in a Gaas/Algaas Superlattice in the Bloch Oscillator Regime0 aThird Harmonic Generation in a GaasAlgaas Superlattice in the Bl aNew York, NYbPlenum Press a161-1630 veds. Hess, Karl, Leburton, J.P., Ravaioli, U.1 aWanke, M., C.1 aMarkelz, A., G.1 aUnterrainer, K.1 aAllen, S., J.1 aBhatt, R. uhttps://www.springer.com/gp/book/978146138035100682nas a2200217 4500008004100000020001400041245011500055210006900170260001100239300001400250490000700264100001400271700002000285700002000305700001800325700001700343700002000360700001900380700001600399856004900415 1995 eng d a0163-182900aQUENCHING OF EXCITONIC QUANTUM-WELL PHOTOLUMINESCENCE BY INTENSE FAR-INFRARED RADIATION - FREE-CARRIER HEATING0 aQUENCHING OF EXCITONIC QUANTUMWELL PHOTOLUMINESCENCE BY INTENSE cFeb 15 a5253-52620 v511 aCerne, J.1 aMarkelz, A., G.1 aSherwin, M., S.1 aAllen, S., J.1 aSundaram, M.1 aGossard, A., C.1 aVanson, P., C.1 aBimberg, D. uhttps://markelz.physics.buffalo.edu/node/26200533nas a2200157 4500008004100000245009100041210006900132260002500201300001200226100001800238700001800256700002000274700001800294700001400312856004900326 1995 eng d00aThird harmonic generation in a GaAs/AlGaAs Superlattice in the Bloch Oscillator Regime0 aThird harmonic generation in a GaAsAlGaAs Superlattice in the Bl aChicago, ILc07/1995 a161-1631 aWanke, M., C.1 aMarkelz, A.G.1 aUnterrainer, K.1 aAllen, S., J.1 aBhatt, R. uhttps://markelz.physics.buffalo.edu/node/31700528nas a2200157 4500008004100000245010600041210006900147260001200216300001400228100001800242700001400260700001800274700001300292700001600305856004900321 1994 eng d00aFrequency Dependence of the Third Order Susceptibility of InAs Quantum Wells at Terahertz Frequencies0 aFrequency Dependence of the Third Order Susceptibility of InAs Q c08/1994 a1193-11961 aMarkelz, A.G.1 aCerne, J.1 aGwinn, E., G.1 aBrar, B.1 aKroemer, H. uhttps://markelz.physics.buffalo.edu/node/31800717nas a2200241 4500008004100000245008100041210006900122300001000191490000900201100002000210700001800230700001900248700001400267700001800281700001900299700001800318700001800336700002000354700002000374700001700394700001500411856004900426 1993 eng d00aFar-infrared nonlinear response of electrons in semiconductor nanostructures0 aFarinfrared nonlinear response of electrons in semiconductor nan a36-470 v18541 aSherwin, M., S.1 aAsmar, N., G.1 aBewley, W., W.1 aCraig, K.1 aFelix, C., L.1 aGaldrikian, B.1 aGwinn, E., G.1 aMarkelz, A.G.1 aGossard, A., C.1 aHopkins, P., F.1 aSundaram, M.1 aBirnir, B. uhttps://markelz.physics.buffalo.edu/node/32000539nas a2200169 4500008004100000245008000041210006900121300001200190490000800202100001900210700001900229700001800248700001600266700001600282700002200298856004900320 1990 eng d00aConversion of 124 and 123 + cupric oxide: microstructure and phase diagram0 aConversion of 124 and 123 cupric oxide microstructure and phase a245-2480 v1691 aMorris, D., E.1 aNickel, J., H.1 aMarkelz, A.G.1 aGronksy, R.1 aFendorf, M.1 aBurmester, C., P. uhttps://markelz.physics.buffalo.edu/node/321