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MANY-ELECTRON EFFECTS ON THE XE 5S NONDIPOLE PHOTOELECTRON ASYMMETRY S. H. Southworth 1 , E. P. Kanter 1 , B. Krässig 1 , R. Guillemin 2 , O. Hemmers 2 , D. W. Lindle 2 , and R. Wehlitz 3 1 Argonne National Laboratory, Argonne, IL 60439* 2 University of Nevada, Las Vegas, NV 89154 3 SRC, University of Wisconsin, Stoughton, WI 53589 Photoionization of the Xe 5s subshell has been extensively studied because of its sensitivity to relativistic and many-electron interactions. Previous studies of the partial cross section and the photoelectron anisotropy parameter are sensitive to the electric-dipole photoionization amplitudes. Recently, the nondipole asymmetry parameter has been calculated and is sensitive to both electric-dipole and electric-quadrupole photoexcitation channels [1,2]. We measured over the 26–140 eV photon energy range at the SRC and combined our results with measurements made over 80–197.5 eV at the ALS. Measurements over the 90–225 eV region were also reported in Ref [3]. In Asymmetry parameter γ 1 0.5 0 -0.5 HF Xe 5s RRPA RPAE -1 50 100 150 200 Photon energy (eV) Fig. 1. Xe 5s nondipole asymmetry parameters measured at the SRC (open circles) and ALS (closed circles) compared with HF (dotted curve), RPAE (dashed curve), and RRPA (solid curve) calculations. Fig. 1, the SRC and ALS results are compared with Hartree-Fock (HF) [1], random-phase approximation with exchange (RPAE) [1], and relativistic random-phase approximation (RRPA) [2] calculations. (The curves plotted in Fig. 1 are based on more accurate calculations than were originally reported in Refs. [1,2]; see Ref. [4].) The parameter varies rapidly near threshold and passes through a minimum near 35 eV. This is due to the 5s p (dipole) amplitude passing through a "Cooper minimum," and is essentially a one-electron effect but is modified by interchannel coupling with the 5p and 4d subshells and by ionic-state satellite channels. The broad maximum near 150 eV results mainly from interchannel coupling with the 4d subshell, which is included in the RPAE and RRPA calculations but not HF. The small feature measured near 160 eV and predicted by the RRPA calculation results from coupling of the 5s d (quadrupole) channels with the 4p f quadrupole shape resonances. A full report on this study is in Ref. [4]. [1] M. Ya. Amusia et al., Phys. Rev. A 63, 052506 (2001). [2] W. R. Johnson and K. T. Cheng, Phys. Rev. A 63, 022504 (2001). [3] S. Ricz et al., Phys. Rev. A 67, 012712 (2003). [4] O. Hemmers et al., Phys. Rev. Lett. 91, 053002 (2003). *The ANL group is supported by the Chemical Sciences, Geosciences, and Biosciences Division, Office of Basic Energy Sciences, Office of Science, U.S. Dept. of Energy, under Contract No. W-31-109-Eng-38.
NEW FEATURES IN THE PHASE DIAGRAM OF CUPRATES Adam Kaminski Department of Physics, University of Wales Swansea, United Kingdom One of the most intriguing properties of the cuprates is their generic phase diagram, where high temperature superconductivity occurs in the proximity of a metal-insulator transition. The understanding of the various phases and their connections is deemed to be the key to solving the problem of high temperature superconductivity. We have used Angle Resolved Photo Emission Spectroscopy (ARPES) to address this problem. By studying the temperature dependence of the bilayer splitting we have found evidence of a cross over between coherent and incoherent electron behavior - long anticipated by a number of theoretical models. We have also shown that a pseudogap exists on the overdoped side of the phase diagram below T c , when the superconductivity is suppressed by application of a sufficiently high current density. However, above certain doping, the pseudogap is no longer observed under the superconducting dome. This may indicate existence of a Quantum Critical Point (QCP) at a doping level between 0.2 and 0.25 holes per Cu atom. Existence of such point could mean close relation between cuprates and in heavy fermion compounds, where QCP is usually surrounded by dome of superconductivity. These results are instrumental in choosing a viable theoretical model of high temperature superconductivity.
Page 2 and 3: Welcome to the 36 th SRC Users’ M
Page 4 and 5: 12:20 - 1:10 Lunch 1:10 -1:45 Poste
Page 6 and 7: Administration Executive Director D
Page 8 and 9: STATUS OF THE SRC BEAMLINES AND INS
Page 10 and 11: ACCELERATOR DEVELOPMENTS Ken Jacobs
Page 12 and 13: HIGH ENERGY RESEARCH POSSIBILITIES
Page 14 and 15: ATOMICALLY UNIFORM THIN FILMS ON SI
Page 16 and 17: calculated binding energies of the
Page 20 and 21: PHOTOELECTRON SPECTROMETRY OF ATOMI
Page 22 and 23: PHOTOEMISSION STUDY OF USb AND UTe
Page 24 and 25: CANADIAN SYNCHROTRON RADIATION FACI
Page 26 and 27: SELF-ASSEMBLY OF BLOCK COPOLYMERS O
Page 28 and 29: A B S T R A C T S
Page 30 and 31: Photoemission spectra, a.u. -0.3 -0
Page 32 and 33: THE INITIAL AND FINAL STATE BANDS I
Page 34 and 35: TRANSITION LAYERS AT BURIED FERROMA
Page 36 and 37: LOW-DIMENSIONAL ELECTRONS AT SILICO
Page 38 and 39: SUBCELLULAR DISTRIBUTION OF MOTEXAF
Page 40 and 41: LINEAR POLARIZATION MEASUREMENTS OF
Page 42 and 43: Fig.1: Photoemission spectra of opt
Page 44 and 45: The sample manipulator has a cool d
Page 46 and 47: Cr and Fe but for these U systems t
Page 48 and 49: [4] G. -H. Gweon, J. W. Allen, and
Page 50 and 51: References [1] S. Cho, Y. Kim, A. D
Page 52 and 53: [3] D. L. Mills, Physical Review B
Page 54 and 55: CHARACTERIZATION OF SULPHATE INTERA
Page 56 and 57: in the data acquisition chamber. Th
Page 58 and 59: spatially resolved chemistry of the
Page 60 and 61: THE RELATIONSHIP BETWEEN PHOSPHATE
Page 62 and 63: PHOTOEMISSION STUDIES OF QUANTUM WE
Page 64 and 65: Ag surface state such that it moves
Page 66 and 67: HIGH-RESOLUTION STUDY OF THE LITHIU
Page 68 and 69:
RELATIVE PARTIAL CROSS SECTIONS AND
Page 70 and 71:
Christian Ast Max-Planck Institute
Page 72 and 73:
David L. Huber Physical Sciences La
Page 74 and 75:
Tom Miller University of Illinois a
Page 76 and 77:
Eric Wiedemann University of Wiscon
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Pete Hagen Phone: (608) 877-2154 Em
Page 80:
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