%0 Journal Article %J Physical Review B %D 2020 %T Linear dichroism infrared resonance in overdoped, underdoped, and optimally doped cuprate superconductors %A Mukherjee, A. %A Seo, J. %A Arik, M. M. %A Zhang, H. %A Zhang, C. C. %A Kirzhner, T. %A George, D. K. %A Markelz, A. G. %A Armitage, N. P. %A Koren, G. %A Wei, J. Y. T. %A Cerne, J. %K Materials Science %K Physics %X

By measuring the polarization changes in terahertz, infrared, and visible radiation over an extended energy range (3-2330 meV), we observe symmetry breaking in cuprate high-temperature superconductors over wide energy, doping, and temperature ranges. We measure the polarization rotation (Re[theta(F)]) and ellipticity (Im[theta(F)]) of transmitted radiation through thin films as the sample is rotated. We observe a twofold rotational symmetry in theta(F), which is associated with linear dichroism (LD) and occurs when electromagnetic radiation polarized along one direction is absorbed more strongly than radiation polarized in the perpendicular direction. Such polarization anisotropies can be generally associated with symmetry breakings. We measure the amplitude of the LD signal and study its temperature, energy, and doping dependence. The LD signal shows a resonant behavior with a peak in the few hundred meV range, which is coincident with the midinfrared optical feature that has been associated with the formation of the pseudogap state. The strongest LD signal is found in underdoped films, although it is also observed in optimally and overdoped samples. The LD signal is consistent with an electronic nematic order which is decoupled from the crystallographic axes as well as novel magnetoelectric effects.

%B Physical Review B %V 102 %P 6 %8 Aug %@ 2469-9950 %G English %9 Article %M WOS:000562627700004 %] 054520 %R 10.1103/PhysRevB.102.054520 %0 Conference Proceedings %B 37th International Conference on Infrared, Millimeter, and Terahertz Waves %D 2012 %T Multi-component response in multilayer graphene revealed through terahertz and infrared magneto-spectroscopy %A Ellis, C. T. %A Stier, A. V. %A George, D. K. %A Tischler, J. G. %A Glaser, E. R. %A Myers-Ward, R. L. %A Tedesco, J. L. %A Eddy, C. R. %A Gaskill, D. K. %A Markelz, A. G. %A Cerne, J. %B 37th International Conference on Infrared, Millimeter, and Terahertz Waves %C Wollongong, Australia %8 9/2012 %G eng %R 10.1109/IRMMW-THz.2012.6380102 %0 Journal Article %J Physical Review Letters %D 2012 %T Terahertz Response and Colossal Kerr Rotation from the Surface States of the Topological Insulator Bi2Se3 %A Aguilar, R. V. %A Stier, A. V. %A Liu, W. %A Bilbro, L. S. %A George, D. K. %A Bansal, N. %A Wu, L. %A Cerne, J. %A Markelz, A. G. %A Oh, S. %A Armitage, N. P. %K bi2te3 %K Physics %X

We 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.

%B Physical Review Letters %V 108 %P 5 %8 Feb %@ 0031-9007 %G English %9 Article %M WOS:000300576000025 %] 087403 %R https://doi.org/10.1103/physrevlett.108.087403 %0 Conference Proceedings %B 2011 36th International Conference on Infrared, Millimeter, and Terahertz Waves %D 2011 %T Magneto Optical Polarization Measurements using THz Polarization Modulation Spectroscopy %A Stier, A. V. %A George, D. %A Markelz, A. G. %A Cerne, J. %E Koch, M. %X

We report a new broad band technique for rapidly measuring the complex Faraday and Kerr rotations in materials such as topological insulators and graphene, combining the distinct advantages of THz time domain spectroscopy and polarization modulation techniques. The performance of the system is demonstrated using GaAs two dimensional electron gas in a magnetic field.

%B 2011 36th International Conference on Infrared, Millimeter, and Terahertz Waves %S International Conference on Infrared Millimeter and Terahertz Waves %I Ieee %C New York %@ 978-1-4577-0509-0 %G English %M WOS:000330296300202 %R 10.1364/JOSAB.29.001406 %0 Journal Article %J Physical Review E %D 2005 %T Large oxidation dependence observed in terahertz dielectric response for cytochrome c %A Chen, J. Y. %A Knab, J. R. %A Cerne, J. %A Markelz, A. G. %K absorption %K binding %K conformation %K dna %K dynamics %K heart ferricytochrome-c %K modes %K Physics %K protein flexibility %K spectroscopy %K state %X

Far infrared dielectric response is used to characterize the collective mode density of states for cytochrome c as a function of oxidation state and hydration using terahertz time domain spectroscopy. A strong absorbance and refractive index increase was observed with the oxidation. A simple phenomenological fitting using a continuous distribution of oscillators reproduces the frequency dependence of the complex dielectric response as well as demonstrates quantitative agreement with a uniform increase in either mode density or polarizability with oxidation in the 5-80 cm(-1) frequency range. Hydration dependence measurements find that a difference in the equilibrium water content for ferri and ferro cytochrome c is not sufficient to account for the large change in terahertz response. The large dielectric increase at terahertz frequencies with oxidation suggests either a significant global softening of the potential and/or a significant increase in polarizability with oxidation.

%B Physical Review E %V 72 %P 4 %8 Oct %@ 1539-3755 %G English %9 Article %M WOS:000232930600005 %] 040901 %R 10.1103/PhysRevE.72.040901 %0 Conference Proceedings %B Mater. Res. Soc. Symp. %D 2004 %T Terahertz measurements of the Photoactive Protein Bacteriorhodopsin mutant D96N: M and P states %A Chen, C.-Y. %A Knab, J. R. %A Cerne, J. %A Hillebrecht, J. R. %A Birge, R. R. %A Markelz, A. G. %X

We 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.

%B Mater. Res. Soc. Symp. %S in Proteins as Materials (ed. V. P. Conteicello, et al) %C Warrendale, PA %V 826 %P pages261–267 %G eng %R 10.1557/PROC-826-V2.6 %0 Conference Proceedings %B Proceedings of the International Symposium on Spectral Sensing Research %D 2003 %T Biosensing with Terahertz Spectroscopy: Ligand Binding Effects %A Chen, J.-Y. %A Cerne, J. %A Markelz, A. G. %B Proceedings of the International Symposium on Spectral Sensing Research %C Santa Barbara, CA %G eng %0 Conference Proceedings %B Proceedings of the International Symposium on Spectral Sensing Research %D 2003 %T Terahertz Biosensors based on Xerogel Substrates %A Chen, J.-Y. %A Cox, W. %A Bright, F. V. %A Cerne, J. %A Markelz, A. G. %B Proceedings of the International Symposium on Spectral Sensing Research %C Santa Barbara, CA %G eng %0 Journal Article %J Applied Physics Letters %D 1996 %T Temperature of quasi-two-dimensional electron gases under steady-state terahertz drive %A Asmar, N. G. %A Cerne, J. %A Markelz, A. G. %A Gwinn, E. G. %A Sherwin, M. S. %A Campman, K. L. %A Gossard, A. C. %K hot-electrons %K Physics %X

We use photoluminescence to study the time-average energy distribution of electrons in the presence of strong steady-state drive at terahertz (THz) frequencies, in a modulation-doped 125 Angstrom AlGaAs/GaAs square well that is held at low lattice temperature TL. We find that the energy distribution can be characterized by an effective electron temperature, T-e(>T-L), that agrees well with values estimated from the THz-illuminated, dc conductivity. This agreement indicates that under strong THz drive, LO phonon scattering dominates both energy and momentum relaxation; that the carrier distribution maintains a heated, thermal form; and that phonon drift effects are negligible. (C) 1996 American Institute of Physics.

%B Applied Physics Letters %V 68 %P 829-831 %8 Feb %@ 0003-6951 %G English %9 Article %M WOS:A1996TT66300035 %! Appl. Phys. Lett.Appl. Phys. Lett. %R 10.1063/1.116547 %0 Journal Article %J Physical Review B %D 1995 %T QUENCHING OF EXCITONIC QUANTUM-WELL PHOTOLUMINESCENCE BY INTENSE FAR-INFRARED RADIATION - FREE-CARRIER HEATING %A Cerne, J. %A Markelz, A. G. %A Sherwin, M. S. %A Allen, S. J. %A Sundaram, M. %A Gossard, A. C. %A Vanson, P. C. %A Bimberg, D. %B Physical Review B %V 51 %P 5253-5262 %8 Feb 15 %@ 0163-1829 %G eng %M WOS:A1995QP75800064 %R 10.1103/PhysRevB.51.5253 %0 Journal Article %J Physical Review B %D 1995 %T RESONANT-ENERGY RELAXATION OF TERAHERTZ-DRIVEN 2-DIMENSIONAL ELECTRON GASES %A Asmar, N. G. %A Markelz, A. G. %A Gwinn, E. G. %A Cerne, J. %A Sherwin, M. S. %A Campman, K. L. %A Hopkins, P. F. %A Gossard, A. C. %B Physical Review B %V 51 %P 18041-18044 %8 Jun 15 %@ 0163-1829 %G eng %M WOS:A1995RF85700093 %R 10.1103/PhysRevB.51.18041 %0 Conference Proceedings %B Proceedings of the International Conference on the Physics of Semiconductors %D 1994 %T Frequency Dependence of the Third Order Susceptibility of InAs Quantum Wells at Terahertz Frequencies %A Markelz, A.G. %A Cerne, J. %A Gwinn, E. G. %A Brar, B. %A Kroemer, H. %B Proceedings of the International Conference on the Physics of Semiconductors %P 1193-1196 %8 08/1994 %G eng