Dr. Georg Ehlers

Lead Instrument Scientist: Cold Neutron Chopper Spectrometer (CNCS), SNS

Education

PhD in Experimental Condensed Matter Physics, the Hahn Meitner Institut, in Berlin, Germany

Description of Research

Dr. Ehlers joined the Spallation Neutron Source (SNS) in 2003 as the lead instrument scientist for beam line 5, the Cold Neutron Chopper Spectrometer (CNCS). CNCS is a high-resolution, direct geometry, cold neutron, inelastic multi-chopper spectrometer, designed to make use of neutrons with an energy of <50 meV.

Before joining the SNS, Dr. Ehlers worked at the Institute Laue-Langevin (ILL), a leading European neutron research facility situated in Grenoble, France for six years. At the ILL, he was instrument-responsible for the spin-echo spectrometers IN11 and IN15, and established a strong research program using the neutron spin echo technique in the study of geometrically frustrated and other exotic magnetic materials. While at the ILL, he also helped launch a project to build a new spin echo instrument known as the Wide Angle Neutron Spin Echo Spectrometer Project (WASP).

Dr. Ehlers has published more than 70 research articles in international peer reviewed journals. He is a referee for the journals of Physical Review Letters, Review of Modern Physics, Physical Review B, Journal of Physics Condensed Matter, Physical Chemistry Chemical Physics, and Nuclear Instruments and Methods.

Selected Publications

G. Ehlers, E. Mamontov, M. Zamponi, A. Faraone, Y. Qiu, A. L. Cornelius, C. H. Booth, K. C. Kam, R. Le Toquin, A. K. Cheetham, and J. S. Gardner, “Frustrated spin correlations in diluted spin ice Ho2-xLaxTi2O7,” J. Phys. Cond. Mat. 20 235206 (2008)

F. J. Bermejo, C. Cabrillo, E. Bychkov, P. Fouquet, G. Ehlers, W. Häussler, D. L. Price, and M. L. Saboungi, “Tracking the Effects of Rigidity Percolation Down to the Liquid State: Relaxational Dynamics of Binary Chalcogen Melts,” PRL 100 245902 (2008)

G. Ehlers, J. S. Gardner, Y. Qiu, P. Fouquet, C. R. Wiebe, L. Balicas, and H. D. Zhou, „Dynamic spin correlations in stuffed spin ice Ho2+xTi2-xO7-d,PRB 77 052404 (2008)

K. C. Rule, G. Ehlers, J. R. Stewart, A. L. Cornelius, P. P. Deen, Y. Qiu, C. R. Wiebe, J. A. Janik, H. D. Zhou, D. Antonio, B. W. Woytko, J. P. Ruff, H. A. Dabkowska, B. D. Gaulin, and J. S. Gardner, “Polarized inelastic neutron scattering of the partially ordered Tb2Sn2O7, PRB 76 212405 (2007)

P. Fouquet, G. Ehlers, B. Farago, C. Pappas, and F. Mezei, “The wide-angle neutron spin echo spectrometer project WASP,” J. Neutron Res. 15 39 (2007)

H. D. Zhou, C. R. Wiebe, Y. J. Jo, L. Balicas, Y. Qiu, J. R. D. Copley, G. Ehlers, P. Fouquet, and J. S. Gardner, “The origin of persistent spin dynamics and residual entropy in the stuffed spin ice Ho2.3Ti1.7O7-d,” J. Phys.: Condens. Matter 19 342201 (2007)

H. Mutka, G. Ehlers, C. Payen, D. Bono, J. R. Stewart, P. Fouquet, P. Mendels, J. Y. Mevellec, N. Blanchard, and G. Collin, “Neutron Spin-Echo Investigation of Slow Spin Dynamics in Kagomé-Bilayer Frustrated Magnets as Evidence for Phonon Assisted Relaxation in SrCr9xGa12‑9xO19,” PRL 97 047203 (2006)

Ehlers, G., “Study of slow dynamic processes in magnetic systems by neutron spin-echo spectroscopy,” J. Phys.: Cond. Mat. 18 R231 (2006)