John Evans Professor
William Halperin's research is focused on low-temperature physics (mainly liquid3He and superconductivity), NMR studies of high-temperature superconductors, and fluid transport in porous media. In an exciting recent development, his research group has discovered how to produce impurity suppression of the thermodynamic transition of superfluid 3He, thus bringing together the practical aspects of fluid confinement in porous media and the basic science of superfluidity. Much of this research involves close cooperation and collaboration with Professor Sauls' theoretical group at Northwestern.
Halperin has been developing 17O NMR as a probe of the magnetic fluctuations associated with magnetic vortices in novel high-Tc superconductors. His research group was the first to take these methods to extremely high magnetic fields, above 40 Tesla, using special facilities at the National High Magnetic Field Laboratory in Tallahassee, Florida.
Halperin is developing acoustic cavity techniques to investigate collective excitations of the 3He superfluid order parameter and he is investigating gapless superfluidity using high-resolution heat capacity methods applied at very low temperatures. He is also studying heavy-fermion superconductivity using NMR on crystals of UPt3. Together with David Seidman of Northwestern's Department of Materials Science and Engineering, Halperin has constructed a facility for crystal growth of heavy-fermion compounds. Their crystals of UPt3 are of the highest quality ever produced. In the area of porous media and molecular diffusion, Halperin is using NMR in conjunction with extremely high-gradient magnetic fields to characterize pore structure and heterogeneous diffusion.
Honors and Awards
- Alfred P. Sloan Fellow
- Yamada Science Foundation Fellow
- Fellow, American Physical Society
- Editor, Progress in Low-Temperature Physics
- Regional Editor for North America for the New Journal of Physics
- Fritz London Memorial Prize, 2017
- Stability of superfluid 3He-B in compressed aerogel, J.I.A. Li, A.M. Zimmerman, J. Pollanen, C.A. Collett, W.J. Gannon, and W.P. Halperin, Phys. Rev. Lett. 112, 115303 (2014).
- Absence of static orbital current magnetism at the apical oxygen site in HgBa2CuO4+δ from NMR, A.M. Mounce, Sangwon Oh, Jeongseop A. Lee, W.P. Halperin, A.P. Reyes, P.L. Kuhns, M.K. Chan, C. Dorow, L. Ji, D. Xia, X. Zhao, M. Greven, Phys. Rev. Lett.111, 187003 (2013).
- The Superfluid Glass Phase of 3He-A, J.I.A. Li, J. Pollanen, A.M. Zimmerman, C.A. Collett, W.J. Gannon, W.P. Halperin, Nature Physics 9, 775-779 (2013).
- Microscopic coexistence of a two-component incommensurate spin density wave with superconductivity in underdoped NaFe0.983Co0.017As, S. Oh, A.M. Mounce, J.A. Lee, W.P. Halperin, C.L. Zhang, S. Carr, P. Dai, A.P. Reyes, P.L. Kuhns, Phys. Rev. B 88, 134518 (2013).
- New chiral phases of superfluid 3He stabilized by anisotropic silica aerogel, J. Pollanen, J.I.A. Li, C.A. Collett, W.J. Gannon, W.P. Halperin and J.A. Sauls, Nature Physics 8, 317-320 (2012).
- Nanoparticle-Loaded Aerogels and Layered Aerogels Cast from Sol-Gel Mixtures, Jiwon Kim, Kideyuki Nakanishi, Johannes Pollanen, Stoyan Smoukov, William P. Halperin, and Bartosz A. Grzybowski, Small, 7, 2568-2572 (2011).
- Spin-density wave near the vortex cores in the high-temperature superconductor Bi2Sr2CaCu2O8+δ, A.M. Mounce, S. Oh, S. Mukhopadhyay, W.P. Halperin, A.P. Reyes, P.L. Kuhns, K. Fujita, M. Ishikado, S. Uchida, Phys. Rev. Lett. 106, 057003 (2011).
- Charge Induced Vortex Lattice Instability, A.M. Mounce, S. Oh, S. Mukhopadhyay, W.P. Halperin, A.P. Reyes, P.L. Kuhns, K. Fujita, M. Ishikado, S. Uchida, Nature Physics 7, 125 (2011).
- The Transition Between Real and Complex Superconducting Order Parameter Phases in UPt3, J.D. Strand, D.J. Bahr, D.J. Van Harlingen, J.P. Davis, W.J. Gannon, W.P. Halperin, Science, 328 (5984), 1368 (2010).
- Evidence for Complex Superconducting Order Parameter Symmetry in the Low Temperature Phase of UPt3 from Josephson Interferometry, J.D. Strand, D.J. Van Harlingen, J.B. Kycia, and W.P. Halperin, Phys. Rev. Lett., 103, 197002 (2009).
- Discovery of a New Excited Pair State in Superfluid 3He, J.P. Davis, J. Pollanen, H. Choi, J.A. Sauls and W.P. Halperin, Nature Physics 4, 571-575 (2008).
- Two-dimensional vortices in superconductors, Bo Chen and W. P. Halperin, et. al., Nature Physics 3, 239 (2007).
- 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).
- Discovery of the Acoustic Faraday Effect in Superfluid 3He-B, Y.Lee, T. Haard, W. P. Halperin, and J.A. Sauls, Nature, 400, 431 (1999).