Southwest Quantum Information and Technology

Nuclear-driven electron spin rotations in a coupled silicon quantum dot and single donor system

Presenting Author: Patrick Harvey-Collard, Carroll group (Sandia)
Contributing Author(s): N. Tobias Jacobson, Martin Rudolph, Jason Dominguez, Gregory A. Ten Eyck, Joel R. Wendt, Tammy Pluym, John King Gamble, Michael P. Lilly, Michel Pioro-Ladrière, and Malcolm S. Carroll

Single donors in silicon are very good qubits. However, a central challenge is to couple them to one another. To achieve this, many proposals rely on using a nearby quantum dot (QD) to mediate an interaction. In this talk, I will demonstrate the coherent coupling of electron spins between a single 31P donor and an enriched 28Si metal-oxide-semiconductor few-electron QD. I show that the electron-nuclear spin interaction can drive coherent rotations between singlet and triplet electron spin states. Moreover, the exchange interaction between the QD and donor electrons can be tuned electrically. The combination of single-nucleus-driven rotations and voltage-tunable exchange provides all elements for future all-electrical control of a spin qubit, and requires only a single dot and no additional magnetic field gradients. These results represent a key step in the realization of multi-donor qubit systems. It also generates exciting new possibilities for nuclear spin qubits. This work was performed, in part, at the Center for Integrated Nanotechnologies, an Office of Science User Facility operated for the U.S. Department of Energy (DOE) Office of Science. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. DOE's National Nuclear Security Administration under contract DE-AC04-94AL85000.

(Session 4 : Thursday from 4:30 pm - 5:00 pm)