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Title: Controlling spin relaxation with a cavity

Spontaneous emission of radiation is one of the fundamental mechanisms by which an excited quantum system returns to equilibrium. For spins, however, spontaneous emission is generally negligible compared to other non-radiative relaxation processes because of the weak coupling between the magnetic dipole and the electromagnetic field. In 1946, Purcell realized that the rate of spontaneous emission can be greatly enhanced by placing the quantum system in a resonant cavity. This effect has since been used extensively to control the lifetime of atoms and semiconducting heterostructures coupled to microwave or optical cavities, and is essential for the realization of high-efficiency single-photon sources. In this paper, we report the application of this idea to spins in solids. By coupling donor spins in silicon to a superconducting microwave cavity with a high quality factor and a small mode volume, we reach the regime in which spontaneous emission constitutes the dominant mechanism of spin relaxation. The relaxation rate is increased by three orders of magnitude as the spins are tuned to the cavity resonance, demonstrating that energy relaxation can be controlled on demand. Our results provide a general way to initialize spin systems into their ground state and therefore have applications in magnetic resonancemore » and quantum information processing. Finally, they also demonstrate that the coupling between the magnetic dipole of a spin and the electromagnetic field can be enhanced up to the point at which quantum fluctuations have a marked effect on the spin dynamics; as such, they represent an important step towards the coherent magnetic coupling of individual spins to microwave photons.« less
Authors:
 [1] ;  [2] ;  [1] ;  [3] ;  [4] ;  [2] ;  [5] ;  [5] ;  [1] ;  [1] ;  [2] ;  [1]
  1. Alternative Energies and Atomic Energy Commission (CEA-Saclay), Gif-sur-Yvette (France)
  2. Univ. College London (United Kingdom)
  3. Alternative Energies and Atomic Energy Commission (CEA-Saclay), Gif-sur-Yvette (France); Inst. of Electronics, Microelectronics and Nanotechnology (IEMN), Villeneuve d'Ascq (France)
  4. Alternative Energies and Atomic Energy Commission (CEA-Saclay), Gif-sur-Yvette (France); Bar-Ilan Univ., Ramat Gan (Israel)
  5. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Publication Date:
Grant/Contract Number:
AC02-05CH11231; 615767; 279781; 630070
Type:
Accepted Manuscript
Journal Name:
Nature (London)
Additional Journal Information:
Journal Name: Nature (London); Journal Volume: 531; Journal Issue: 7592; Journal ID: ISSN 0028-0836
Publisher:
Nature Publishing Group
Research Org:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Alternative Energies and Atomic Energy Commission (CEA-Saclay), Gif-sur-Yvette (France)
Sponsoring Org:
USDOE; European Research Council (ERC)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; quantum mechanics; quantum information; quantum optics
OSTI Identifier:
1379133