Wisconsin Alumni Research Foundation

Susan Nan Coppersmith

Mark A Eriksson

Mark Gregory Friesen

Donald E Savage

Robert J Joynt

John King Gamble

Daniel R Ward

Semiconductor heterostructures, methods of making the heterostructures, and quantum dots and quantum computation devices based on the heterostructures are provided. The heterostructures include a quantum well of strained silicon seeded with a relatively low concentration of germanium impurities disposed between two quantum barriers of germanium or a silicon-germanium alloy. The quantum wells are characterized in that the germanium concentration in the wells has an oscillating profile that increases the valley splitting in the conduction band of the silicon quantum well.

Silicon-germanium heterostructures with quantum wells having oscillatory germanium concentration profiles for increased valley splitting

A quantum computing system and method for performing quantum computation is provided. In some aspects, the system includes at least one charge qubit comprising a quantum dot assembly prepared with a symmetric charge distribution, wherein the symmetric charge distribution is configured to reduce a coupling between the charge qubit and a charge noise source. The system also includes a controller for controlling the at least one charge qubit to perform a quantum computation. The system further includes an output for providing a report generated using information obtained from the quantum computation performed.

System and method for quantum computation using symmetrical charge qubits

A quantum semiconductor device is provided. The quantum semiconductor device includes a quantum heterostructure, a dielectric layer, and an electrode. The quantum heterostructure includes a quantum well layer that includes a first 2DEG region, a second 2DEG region, and a third 2DEG region. A first tunnel barrier exists between the first 2DEG region and the second 2DEG region. A second tunnel barrier exists between the second 2DEG region and the third 2DEG region. A third tunnel barrier exists either between the first 2DEG region and the third 2DEG region. The dielectric layer is formed on the quantum heterostructure. The electrode is formed on the dielectric layer directly above the first tunnel barrier.

Growing community of inventors

Madison, WI, United States of America

Susan Nan Coppersmith