Entangling remote spins through optically active mediators

When?

Thursday 16 February 2012, 13:00 to 14:00

Where?

ATI Seminar room - 02ATI02

Open to:

Staff, Students

Speaker:

Dr Brendon Lovett, Heriot-Watt University

A promising way to build a quantum computer is to use different qubit species for different roles. For example, it is desirable to store quantum information in long lived memory qubits, but to use easier-to-manipulate species when performing quantum logic gates.

I will here discuss two papers [1,2] in which we show how to exploit at least two different spin species in the execution of an entangling quantum logic gate. The first, which is based on an architecture first proposed by Stoneham, Fisher and Greenland [3], uses a control qubit to mediate an exchange coupling of two storage qubits. I will show that this scheme works for a very wide variety of coupling strengths, including unequal coupling of the two storage bits to the control.

In the second work, I will demonstrate the feasibility of using an optically excited electronic spin triplet state on an endohedral fullerene to entangle nuclear spin qubits. The theoretical proposal will be backed up by some spin resonance experiments and DFT calculations.

[1] E. M. Gauger, P. P. Rohde, A. M. Stoneham and B. W. Lovett, New J. Phys. 10 073027 (2008)
[2] M. Schaffry et al.,  Phys. Rev. Lett. 104 200501 (2010)
[3] A. M. Stoneham, A. J. Fisher and P. T. Greenland,  J. Phys. Condens. Matter 15 L447 (2003)