October 26, Mike Manfra, Purdue University

image538913:00 PM in Room 210, 8 St. Mary’s Street

Refreshments served at 2:45 PM

Pushing Materials to the Extreme: Creating GaAs Heterostructures for Quantum Computing

Abstract: The possibility of coherent manipulation of quantum-mechanical degrees of freedom in solid-state devices holds great promise for the future of quantum information processing.  In semiconducting materials two leading candidates for implementation of quantum bits, or qubits, include the spin-qubit in coupled quantum dots and the topological qubit that exploits unique properties of certain fractional quantum Hall states.  To realize solid-state qubits we must learn to control decoherence. Decoherence occurs through a multitude of processes in which information stored in a quantum-mechanical state is lost through interactions with the surrounding environment. It is apparent that many of the technical challenges associated with solid-state qubits are related to the underlying properties of the GaAs heterostructures from which they are constructed. In this talk, I will describe how we actually create such physical systems in the laboratory using molecular beam epitaxy (MBE). Both spin-qubit and topological qubit devices present unique challenges for materials engineering. In particular I will discuss how our group attempts to push the limits of MBE technology to coax new physics at ever finer energy scales, potentially enabling new topological devices, and how we attempt to design and fabricate novel heterostructures for next-generation spin-qubits.

Biography: Michael Manfra graduated from Harvard University in 1992 with an A.B. in Physics.  He completed his Ph. D in Physics at Boston University in 1999 under the supervision of Prof. B. Goldberg.  From 1999 through 2000 Manfra was a Postdoctoral Member of Technical Staff at Bell Laboratories in Murray Hill, NJ.  In 2001 he was promoted to Member of Technical Staff at Bell Labs.  In 2009 Manfra joined the faculty at Purdue University as the William F. and Patty J. Miller Associate Professor of Physics, Materials Engineering and Electrical and Computer Engineering.  His research at Purdue focuses on exploration of correlated electron physics and quantum computing in ultra-pure semiconductors.


Faculty Host: Bennett Goldberg

Student Host: Sebastian Rémi