Ultrafast Optical Control of Spin Qubits

Project Description

In this work, Press et al. demonstrate the use of ultrafast (~2 picosecond) pulses to manipulate an electron spin trapped in a quantum dot. The paper shows that full rotations about one spin axis can be made using such pulses, and that in combination with Larmor precession caused by the application of a large, static magnetic field, it is possible to manipulate the spin to point in any direction on the Bloch sphere in less than 50 picoseconds.

Figure 1. The energy level structure of the quantum dot spin system, and the experimental setup.

Figure 2. Rabi oscillations from the ultrafast control technique, which directly show how increased angles of rotation about one spin axis can be achieved by simply increasing the optical power of the rotation pulses.

Publications

Press et al. “Complete quantum control of a single quantum dot spin using ultrafast optical pulses.” Nature 456, 218 – 221 (2008). [http://dx.doi.org/10.1038/nature07530]

Project Members

Dr. David Press

Kristiaan De Greve

Dr. Thaddeus Ladd

Prof. Yoshihisa Yamamoto

External Collaborators

Funding Acknowledgments