Harvard University Department of Physics

• Faculty by Name
• Faculty by Research Area

ADDRESS/TELEPHONE
Jefferson 353
17 Oxford Street
Cambridge, MA 02138
(617) 495-3201

STAFF SUPPORT
Sutopa Dasgupta
Jefferson 354
(617) 495-8247




LINKS
Research Group
Center for Ultracold Atoms

Physics Department Faculty:

John M. Doyle

Professor of Physics

PhD 1991, MIT

John Doyle’s research centers on trapping neutral particles to perform low energy fundamental physics experiments. Trapping increases the precision of these experiments by lengthening interaction times, providing a well-controlled environment, and allowing (in the case of molecules and atoms) for further cooling. Doyle is currently working to realize new techniques to trap ultra-cold neutrons, molecules, and atoms.

The Doyle group has pioneered a general technique for loading atoms and molecules into traps. First demonstrated with atomic europium and chromium and molecular CaH, the technique uses cryogenically cooled helium buffer gas to cool atoms to below 1 Kelvin. The cold atoms are then loaded into a magnetic trap and then evaporatively cooled to ultracold temperatures. The technique relies only on elastic collisions with the buffer gas and thus should be applicable to molecules. Heavy, highly polar molecules are ideally suited to the search for a permanent electric dipole moment (EDM) in the electron. The discovery of an EDM in these experiments would indicate new physics beyond the standard model. Cold, trapped molecules would greatly improve the limits of such a search. In addition, ultracold molecules can be used to study new quantum phase transitions. Work is also ongoing to produce ultra-intense atom lasers.

In addition, work is ongoing to trap ultra-cold neutrons (UCN). Trapped UCN should allow for a large improvement in the precision of the measured neutron beta-decay lifetime and asymmetry coefficient. These measurements can be combined to fully determine the weak force coupling constants and used to test parts of the standard model. Trapping of UCN can be realized by using a magnetic trap in conjunction with a superthermal scattering medium. Superfluid helium is used in the experiments currently under way. Detection of neutrons is via XUV scintillation of beta particles in liquid helium.