Alexandria Digital Research Library

Quantum control and engineering of single spins in diamond

Author:
Toyli, David M.
Degree Grantor:
University of California, Santa Barbara. Physics
Degree Supervisor:
David D. Awschalom
Place of Publication:
[Santa Barbara, Calif.]
Publisher:
University of California, Santa Barbara
Creation Date:
2013
Issued Date:
2013
Topics:
Physics, Quantum and Physics, Condensed Matter
Keywords:
Single spin
Quantum information
Electron spin resonance
Spintronics
Thermometry
Quantum control
Genres:
Dissertations, Academic and Online resources
Dissertation:
Ph.D.--University of California, Santa Barbara, 2013
Description:

The past two decades have seen intensive research efforts aimed at creating quantum technologies that leverage phenomena such as coherence and entanglement to achieve device functionalities surpassing those attainable with classical physics. While the range of applications for quantum devices is typically limited by their cryogenic operating temperatures, in recent years point defects in semiconductors have emerged as potential candidates for room temperature quantum technologies. In particular, the nitrogen vacancy (NV) center in diamond has gained prominence for the ability to measure and control its spin under ambient conditions and for its potential applications in magnetic sensing. Here we describe experiments that probe the thermal limits to the measurement and control of single NV centers to identify the origin of the system's unique temperature dependence and that define novel thermal sensing applications for single spins.

We demonstrate the optical measurement and coherent control of the spin at temperatures exceeding 600 K and show that its addressability is eventually limited by thermal quenching of the optical spin readout. These measurements provide important information for the electronic structure responsible for the optical spin initialization and readout processes and, moreover, suggest that the coherence of the NV center's spin states could be harnessed for thermometry applications. To that end, we develop novel quantum control techniques that selectively probe thermally induced shifts in the spin resonance frequencies while minimizing the defect's interactions with nearby nuclear spins. We use these techniques to extend the NV center's spin coherence for thermometry by 45-fold to achieve thermal sensitivities approaching 10 mK Hz-1/2 . We show the versatility of these techniques by performing measurements in a range of magnetic environments and at temperatures as high as 500 K.

Together with diamond's ideal thermal, mechanical, and chemical properties, these measurements suggest that NV center sensors could be employed in a diverse range of applications such as intracellular thermometry, microfuidic thermometry, and scanning thermal microscopy. Finally, while the development of NV center technologies is motivated by the desirable properties of isolated defects in bulk diamond, the realization of many of these technologies, such as those using the spin as a proximal sensor, require a means to control the placement of NV centers within the diamond lattice. We demonstrate a method to pattern defect formation on sub-100-nm length scales using ion implantation and electron beam lithography techniques. The ability to engineer large scale arrays of NV centers with this method holds promise for a variety of applications in quantum information science and nanoscale sensing.

Physical Description:
1 online resource (122 pages)
Format:
Text
Collection(s):
UCSB electronic theses and dissertations
ARK:
ark:/48907/f3jm27mp
ISBN:
9781303540905
Catalog System Number:
990040925400203776
Rights:
Inc.icon only.dark In Copyright
Copyright Holder:
David Toyli
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