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 Look Who's at the Lab: William Halperin
In Look Who's at the Lab, we profile some of the hundreds of scientists who visit our lab every year.
Halperin and his students during a visit to the lab. From left to right: Halperin, Eric Sigmund, Vesna Mitrovic, Ned Calder and Will Thomas.
The Basics
The Research
Quick Q & A
Publications
Title: John Evans Professor of Physics, Northwestern University
Mag Lab user since: 1995
Number of visits to the lab: About two dozen research visits
Dates of most recent visit: Jan. 13-19, 2008.
Distance traveled: About 964 miles (1,553 km)
Research Interests:
Superconductivity in high magnetic fields.
Web sites: http://www.physics.northwestern.edu/research/halperin.html, http://spindry.phys.northwestern.edu/
Email: w-halperin@northwestern.edu
Title: Flux dynamics, phase diagram and vortex cores in Bi-2212 at high magnetic fields.
Participants: Sutirtha Mukhopadhyay, Andrew Mounce, Sangwon Oh (Northwestern University), and Arneil Reyes and Phil Kuhns (both of the Mag Lab)
Synopsis: "Superconductors have two key characteristics. They expel
magnetic field and they conduct electrical current with zero resistance. However, both properties are compromised in
high magnetic fields which can penetrate the
material and create a mixed state of quantized vortices each comprised of a microscopic "tornado" of electrical currents. At temperatures that are sufficiently high, the
vortices can move, dissipating energy and destroying the zero resistance state. One of the central problems for
applications of high temperature superconductivity is the
stabilization of these vortices to ensure zero electrical
resistance. To better understand the basic properties of the superconductor, we investigate the dynamic behavior and the static structure of these vortices using nuclear magnetic resonance of selected oxygen atoms in the host material. The atoms we target behave much like small compass needles, reporting the effects of moving electrical currents and changing magnetic fields but on a microscopic level sensitive to distances less than 1 nanometer."
Facility: DC Field Facility, Tallahassee
Equipment: Solid State NMR spectrometer (model: MagRes2000 ) and cryogenic probes.
Techniques: Nuclear magnetic resonance, mainly of the rare isotope 17-oxygen.
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Favorite thing about working at the lab:
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The Mag Lab is the most exciting research laboratory in the world.
There are always colleagues from many backgrounds and from different institutions with new projects and ideas. The technical infrastructure is at the highest level – not just for the production of record high magnetic fields, but additionally for state-of-the-art measurement techniques and instrumentation. The environment for training graduate students is unique here and extremely effective. Of my former students who have worked or are now working at the Mag Lab, four are faculty at various universities. These include Mark Meisel and Yoonseok Lee at the University of Florida; Prof. Vesna Mitrovic of Brown University; and Prof. Guillaume Gervais, McGill University. Three have been awarded Sloan Fellowships. |
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Thing you miss most about home when you’re here:
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Coffee.
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Your proudest science moment:
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The first run in the Magnet Lab's hybrid magnet, where Vesna Mitrovic was able to spatially resolve the cores of vortices in a high temperature superconductor, later published in Nature.
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What keeps you awake at night:
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Designing a new experiment.
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The most unscientific thing about you:
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I love puppies and little kids.
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Your hero:
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My uncle Wendell Furry.
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Last book you read:
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When We Were Orphans, by Kazuo Ishiguro
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Parting thoughts on science today:
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Science achievement offers great promise for societal benefits and intellectual development not bounded by geographic or ethnologic demographics. Investing in scientific education is a sure bet.
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- Two-dimensional vortices in superconductors, Bo Chen and W. P. Halperin, et. al., Nature Physics 3 239 (2007).
- Penetration depth and anisotropy of MgB2 from 11B NMR, Bo Chen, Pratim Sengupta, Eric E. Sigmund, and W. P. Halperin, et, al., New Journal of Physics 8 274 (2006).
- Effect of Strong Magnetic Fields on Superfluid 3He in 98% Porosity Aerogel, H.C. Choi, A.J. Gray, C.L. Vicente, J.S. Xia, G. Gervais, W.P. Halperin, N. Mulders, and Y. Lee, J. Low Temp. Phys. 138, 107 (2004).
- NMR Lineshape in the Vortex Lattice State of Near-Optimally Doped YBa2Cu3O7-d, V. F. Mitrovic, E. E. Sigmund, and W.P. Halperin, Physica C 388-389, 629 (2003).
- Antiferromagnetism in the Vortex Cores of YBa2Cu3O7-d, V. F. Mitrovic, E. E. Sigmund, W.P. Halperin, A.P. Reyes, P. Kuhns, W.G. Moulton, Phys. Rev B. Rapid 67, 220503 (2003).
- Spatially Resolved Electronic Structure Inside and Outside the Vortex Core of a High Temperature Superconductor, V. F. Mitrovic, E. E. Sigmund, M. Eschrig, H. N. Bachman, W.P. Halperin, A.P. Reyes, P. Kuhns, and W.G. Moulton, Nature 413, 501 (2001).
- Polar Signal Averaging, G.W. Thomas, H.N. Bachman, E.E. Sigmund, V.F. Mitrovic, E.S. Calder, and W.P. Halperin, Concepts in Mag. Res. 14, 359 (2002).
- Acoustic Faraday Effect in Superfluid 3He-B, Y. Lee, T. Haard, J. A. Sauls, and W. P. Halperin, Physica B 280, 106 (2000).
- Superconducting Fluctuation Effects on the Spin-lattice Relaxation Rate in YBa2Cu3O6.95, V.F. Mitrovic, H.N. Bachman, W.P. Halperin, M. Eschrig, J.A. Sauls, A.P. Reyes, P. Kuhns, and W.G. Moulton, Phys. Rev. Lett. 82, 2784 (1999).
More publications
Date posted: January 2008
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