AVS 50th International Symposium
    Nanometer Structures Monday Sessions
       Session NS-MoM

Paper NS-MoM5
Spin Based Qubit Fabrication in SiGe

Monday, November 3, 2003, 9:40 am, Room 316

Session: Quantum Dots and Nanoscale Devices
Presenter: L.J. Klein, University of Wisconsin, Madison
Authors: L.J. Klein, University of Wisconsin, Madison
K.A. Slinker, University of Wisconsin, Madison
J.L. Truitt, University of Wisconsin, Madison
M. Friesen, University of Wisconsin, Madison
D.W. van der Weide, University of Wisconsin, Madison
S.N. Coppersmith, University of Wisconsin, Madison
R. Joynt, University of Wisconsin, Madison
M.A. Eriksson, University of Wisconsin, Madison
Correspondent: Click to Email
A promising approach to solid-state implementation of quantum computers is electron spins in silicon devices. The design incorporates vertical and lateral tunneling into quantum dots defined by nanostructured top gates in the 2DEG of a strained Si quantum well. The potential in the two-dimensional electron gas is modulated by the voltages applied to the top metallic gates. Work is underway to fabricate quantum point contact and quantum dots in strained Si layer and quantum phenomena are investigated related to discrete charge variations. The ultimate goal is the fabrication of qubit: a quantum dot with single electron occupancy with a well defined spin state which is immune from decoherence. This scalable approach allows entanglement of two qubits by varying the voltage applied to top gates separating two quantum dots. Recent measurements of spin lifetime in stained SiGe structures shows decoherence times larger than micro seconds. This large decoherence time should allow many qubit logic operations, initialization, and read-out of a single spin qubit.