Coherent control via weak measurements in P 31 single-atom electron and nuclear spin qubits

Coherent control via weak measurements in P 31 single-atom electron and nuclear spin qubits

Muhonen, J. T. (University of New South Wales; University of Jyväskylä)
Dehollain Lorenzana, J.P. (TU Delft QCD/Vandersypen Lab; University of New South Wales)
Laucht, A. (University of New South Wales; Simon Fraser University)
Simmons, S. (University of New South Wales; Simon Fraser University)
Kalra, R. (University of New South Wales; University of Queensland)
Hudson, F. E. (University of New South Wales)
Dzurak, A. S. (University of New South Wales)
Morello, A. (University of New South Wales)
Jamieson, D. N. (University of Melbourne)
McCallum, J. C. (University of Melbourne)
Itoh, K. M. (Keio University)

2018

The understanding of weak measurements and interaction-free measurements has greatly expanded the conceptual and experimental toolbox to explore the quantum world. Here we demonstrate single-shot variable-strength weak measurements of the electron and nuclear spin states of a P31 single-atom donor in silicon. We first show how the partial collapse of the nuclear spin due to measurement can be used to coherently rotate the spin to a desired pure state. We explicitly demonstrate that phase coherence is preserved with high fidelity throughout multiple sequential single-shot weak measurements and that the partial state collapse can be reversed. Second, we use the relation between measurement strength and perturbation of the nuclear state as a physical meter to extract the tunnel rates between the P31 donor and a nearby electron reservoir from data conditioned on observing no tunneling events. Our experiments open avenues to measurement-based state preparation, steering and feedback protocols for spin systems in the solid state, and highlight the fundamental connection between information gain and state modification in quantum mechanics.

http://resolver.tudelft.nl/uuid:d496ce8e-e948-4f55-a475-924fc8b4c5ed

https://doi.org/10.1103/PhysRevB.98.155201

2469-9950

Physical Review B, 98 (15)

Institutional Repository

journal article

© 2018 J. T. Muhonen, J.P. Dehollain Lorenzana, A. Laucht, S. Simmons, R. Kalra, F. E. Hudson, A. S. Dzurak, A. Morello, D. N. Jamieson, J. C. McCallum, K. M. Itoh