Eur. Phys. J. D 48, 293-300 (2008)
https://doi.org/10.1140/epjd/e2008-00101-8

Creation of entanglement between two electron spins induced by many spin ensemble excitations

¹ Department of Physics, Tsinghua University, Beijing, 100084, P.R. China
² Department of Physics, University of Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland
³ Tsinghua National Laboratory for Information Science and Technology, Beijing, 100084, P.R. China
⁴ Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing, 100080, P.R. China

Corresponding author: ^a suncp@itp.ac.cn

Received: 8 October 2007
Revised: 1 April 2008
Published online: 30 May 2008

Abstract

We theoretically explore the possibility of creating spin entanglement by simultaneously coupling two electronic spins to a nuclear ensemble. By microscopically modeling the spin ensemble as a single mode boson field, we use the time-dependent Fröhlich transformation (TDFT) method developed recently [Y. Li, C. Bruder, C.P. Sun, Phys. Rev. A 75, 032302 (2007)] to calculate the effective coupling between the two spins. Our investigation shows that the total system realizes a solid state based architecture for cavity QED. Exchanging such kind of effective boson in a virtual process can result in an effective interaction between two spins. It is discovered that a maximum entangled state can be obtained when the velocity of the electrons matches the initial distance between them in a suitable way. Moreover, we also study how the number of collective excitations influences the entanglement. It is shown that the larger the number of excitation is, the less the two spins entangle each other.