Physics Department Faculty:
Ronald L. Walsworth
Senior LecturerPhD 1991, Harvard University
Ron Walsworth's research group pursues a wide range of experimental investigations, including the development of atomic clocks; precise tests of physical laws and symmetries; 'stored light' and applications to quantum information; studies of porous and granular media; and biomedical imaging with applications to pulmonary physiology. Many of these investigations exploit state-selected atoms: e.g., noble gases that are nuclear-spin-polarized by spin-exchange optical pumping, or rubidium atoms placed into 'dark states' by laser Raman scattering. Extensive use is also made of high-frequency-stability masers and NMR imaging and scattering.
Recent research highlights include: the most sensitive tests of Lorentz and CPT symmetry for the neutron and proton; demonstration of MRI of the lung at very low magnetic fields using inhaled, spin-polarized noble gas; and co-development of the 'stored light' technique, in which quantum states of photons are coherently and reversibly mapped into an atomic ensemble by adiabatically reducing the group velocity of propagating light pulses to zero.
- Y. Xiao, I. Novikova, D.F. Phillips, R.L. Walsworth, "Diffusion-induced Ramsey narrowing", Phys. Rev. Lett. 96, 043601 (2006).
- S. Zibrov, I. Novikova, D.F. Phillips, V.A. Taichenachev, V.I. Yudin, R.L. Walsworth, A.S. Zibrov, "Three-photon-absorption resonance for all-optical atomic clocks", Phys. Rev. A 72, 011801(R) (2005).
- R.W. Mair, M.I. Hrovat, S. Patz, M.S. Rosen, I.C. Ruset, G.P. Topulos, L.L. Tsai, J.P. Butler, F.W. Hersman, R.L. Walsworth, "3He Lung Imaging in an Open Access, Very-Low-Field Human MRI System", Magnetic Resonance in Medicine 53, 745 (2005).
- F. Cane, D. Bear, D.F. Phillips, M.S. Rosen, C.L. Smallwood, R.E. Stoner, R.L. Walsworth, V.A. Kostelecky, "Bound on Lorentz- and CPT-Violating Boost Effects for the Neutron", Phys. Rev. Lett. 93, 230801 (2004).
- C.H. van der Wal, M.D. Eisaman, A. Andre, R.L. Walsworth, D.F. Phillips, A.S. Zibrov, M.D. Lukin, "Atomic Memory for Correlated Photon States", Science 301, 196 (2003).
- X. Yang, C. Huan, D. Candela, R.W. Mair, R.L. Walsworth, "Measurements of Grain Motion in a Dense, Three Dimensional Granular Fluid", Phys. Rev. Lett. 88, 044301(2002).
- D.F. Phillips, M.A. Humphrey, E.M. Mattison, R.E. Stoner, R.F.C. Vessot, R.L. Walsworth, "Limit on Lorentz and CPT violation of the proton using a hydrogen maser", Phys. Rev. D 63, 111101 (2001).
- D.F. Phillips, A. Fleischhauer, A. Mair, R.L. Walsworth, M.D. Lukin, "Storage of light in atomic vapor", Phys. Rev. Lett. 86, 783 (2001).
- D. Bear, R.E. Stoner, R.L. Walsworth, V.A. Kostelecky, C.D. Lane, "Limit on Lorentz and CPT violation of the neutron using a two species noble gas maser", Phys. Rev. Lett. 85, 5038 (2000).
- R.W. Mair, G.P. Wong, D. Hoffmann, M.D. Hurlimann, S. Patz, L.M. Schwartz, R.L. Walsworth, "Probing porous media with gas diffusion NMR", Phys. Rev. Lett. 83, 3324 (1999).
- C.H. Tseng, G.P. Wong, V.R. Pomeroy, R.W. Mair, D.P. Hinton, D. Hoffmann, R.E. Stoner, F.W. Hersman, D.G. Cory, R.L. Walsworth, "Low field MRI of laser polarized noble gas", Phys. Rev. Lett. 81, 3785 (1998).