00714nas a2200169 4500008004100000020002200041245008800063210006900151520016300220100001500383700001900398700002000417700001500437700002100452700002200473856004900495 2019 eng d a978-1-5386-8285-200aStationary Sample Anisotropic THz Spectroscopy using Discretely Tunable THz Sources0 aStationary Sample Anisotropic THz Spectroscopy using Discretely 3 a

We demonstrate anisotropic THz spectroscopy of sucrose using newly developed compact discretely tunable THz sources for turn-key spectroscopic systems.

1 aLaFave, T.1 aGeorge, D., K.1 aMarkelz, A., G.1 aMcNee, Ian1 aKozlov, Vladimir1 aSchunemann, Peter uhttps://markelz.physics.buffalo.edu/node/23001623nas a2200205 4500008004100000020001400041245011600055210006900171260000800240300001200248490000600260520099500266100002001261700001801281700001801299700002001317700001501337700001601352856004901368 1994 eng d a0268-124200aSUBCUBIC POWER DEPENDENCE OF 3RD-HARMONIC GENERATION FOR INPLANE, FAR-INFRARED EXCITATION OF INAS QUANTUM-WELLS0 aSUBCUBIC POWER DEPENDENCE OF 3RDHARMONIC GENERATION FOR INPLANE  cMay a634-6370 v93 a

Large third-order, free-carrier nonlinear susceptibilities, chi(3) (to approximately 0.2 esu), and subcubic dependence of the third-harmonic power on the incident intensity, have been observed between 19 cm-1 and 23 cm-1 for InAs/AlSb quantum wells with electron sheet densities between 2.5 x 10(12) cm-2 and 8 X 10(12) cm-2. We find that the transmission of the fundamental, and the samples' DC conductivity, decrease with increasing incident intensity, indicating a large rise in the scattering rate. Using the intensity-dependent transmission to account for absorption in the sample is not sufficient to recover a cubic power law for the third-harmonic intensity. In addition, given the increased scattering rate indicated by the conductivity data, the bulk free-carrier chi(3) due to non-parabolicity should decrease dramatically with increasing fundamental intensity, contrary to our results. Thus, non-parabolicity alone cannot account for the observed third-harmonic response.

1 aMarkelz, A., G.1 aAsmar, N., G.1 aGwinn, E., G.1 aSherwin, M., S.1 aNguyen, C.1 aKroemer, H. uhttps://markelz.physics.buffalo.edu/node/26709915nas a2200181 4500008004100000245006500041210006300106490000700169520935100176100001909527700002009546700001909566700002109585700001909606700002109625700002009646856006709666 1991 eng d00aSite-selective oxygen-isotope substitution in YBa2Cu3O7−δ0 aSiteselective oxygenisotope substitution in YBa2Cu3O7−δ0 v443 a

We report selective substitution of oxygen-18 and oxygen-16 isotopes into the inequivalent oxygen lattice sites in YBa2Cu3O7δ. The technique involves gas-phase diffusion and exploits the site dependence of diffusion rates. The CuO2-plane [O(2),O(3)] sites of YBa2Cu3O7δ can be filled with 18O while the apical [O(4)] and CuO-chain sites [O(1)] contain 16O (the opposite distribution can also be made). The site-selective isotope occupation has been confirmed by Raman spectroscopy. Our method will permit experiments to determine the contributions of the different oxygen sites to the isotope effect, in order to locate the pairing interaction within the unit cell.

1 aMorris, D., E.1 aMarkelz, A., G.1 aWei, J., Y. T.1 aHuitgren, C., T.1 aNickel, J., H.1 aHamilton, J., C.1 aMcCarty, K., F. uhttps://journals.aps.org/prb/abstract/10.1103/PhysRevB.44.955600501nas a2200181 4500008004100000020001400041245004400055210004400099260001000143300001400153490000700167100001900174700001900193700002000212700001900232700001900251856004900270 1988 eng d a0163-182900aSMALL OXYGEN ISOTOPE SHIFT IN YBA2CU3O70 aSMALL OXYGEN ISOTOPE SHIFT IN YBA2CU3O7 cApr 1 a5936-59390 v371 aMorris, D., E.1 aKuroda, R., M.1 aMarkelz, A., G.1 aNickel, J., H.1 aWei, J., Y. T. uhttps://markelz.physics.buffalo.edu/node/27900725nas a2200217 4500008004100000020001400041245015500055210006900210260001000279300001600289490000700305100001900312700001200331700001700343700002100360700001900381700002000400700001900420700001900439856004900458 1988 eng d a0163-182900aSPECIFIC-HEAT MEASUREMENTS ON SUPERCONDUCTING BI-CA-SR-CU AND TL-CA-BA-CU OXIDES - ABSENCE OF A LINEAR TERM IN THE SPECIFIC-HEAT OF BI-CA-SR-CU OXIDES0 aSPECIFICHEAT MEASUREMENTS ON SUPERCONDUCTING BICASRCU AND TLCABA cDec 1 a11942-119450 v381 aFisher, R., A.1 aKim, S.1 aLacy, S., E.1 aPhillips, N., E.1 aMorris, D., E.1 aMarkelz, A., G.1 aWei, J., Y. T.1 aGinley, D., S. uhttps://markelz.physics.buffalo.edu/node/277