Harvard University Department of Physics

• Faculty by Name
• Faculty by Research Area

ADDRESS/TELEPHONE
Pierce 234
29 Oxford Street
Cambridge, MA 02138
(617) 495-3296

STAFF SUPPORT
Naomi Brave
Pierce 228
(617) 495-32961027




LINKS
Research Group
Nanoscale Science and Engineering Center
Center for Nanoscale Systems

Physics Department Faculty:

Robert M. Westervelt

Mallinckrodt Professor of Applied Physics and of Physics

PhD 1977, University of California, Berkeley

Westervelt's group investigates the quantum behavior of electrons inside nanoscale structures and develops tools for the manipulation of biological systems.

The motion of electrons through a nanoscale system is inherently quantum mechanical. Electrons move as waves through a two-dimensional electron gas and are trapped as particles inside a quantum dot. Westervelt's group uses scanning probe microscopy at low temperatures to image the flow of electron waves (Topinka et al. 2003) and cyclotron orbits produced by magnetic focusing in a 2DEG (Aidala et al. 2007). They can also image a GaAs quantum dot that holds just one electron (Fallahi et al. 2005). Semiconductor nanowires can form even smaller structures. With Lars Samuelson, they are imaging one-electron, hockey-puck shaped InAs quantum dots grown inside an InAs/InP nanowire (Bleszynski et al. 2007).

Control of individual electrons provides new approaches for ultrasmall electronics, spintronics and quantum information processing. Following their original research to make an artificial molecule (Livermore et al. 1996), Westervelt's group has developed double and triple dots in which the occupation of each dot can be reduced to one electron (Vidan et al. 2006). With Charles Lieber, they have transformed a Ge/Si core/shell nanowire into a Josephson junction by using superconducting Al contacts (Xiang et al. 2006). The width of the conducting channel can be reduced all the way to zero by a gate, testing superconductivity in very narrow systems.

Custom semiconductor chips provide new opportunities for the observation and control of biological cells and systems. Westervelt's group has combined the power of an integrated circuit with the biocompatibility of a microfluidic system to make hybrid IC / Microfluidic chips. A two-dimensional array of microcoils in the IC acts as a display with magnetic pixels can be turned on, to trap and move single biological cells in the microfluidic system above (Lee et al. 2006). A chip that uses dielectrophoresis to move non-magnetic objects has also been developed (Hunt et al. 2004).

Robert Westervelt is Director of the NSF-funded Nanoscale Science and Engineering Center at Harvard University , which includes participants at MIT and UC Santa Barbara, and supports outreach through the Museum of Science , Boston . More information is available at the Center's website nsec.harvard.edu.