ar X iv : 1 20 1 . 27 36 v 3 [ qu an t - ph ] 2 8 Fe b 20 12 A measurement scheme for purity based on two two - body gates

ar X iv : 0 80 8 . 36 90 v 1 [ qu an t - ph ] 2 7 A ug 2 00 8 Entanglement dynamics of two - qubit system in different types of noisy channels ∗

X iv :0 80 8. 36 90 v1 [ qu an tph ] 2 7 A ug 2 00 8 Entanglement dynamics of two-qubit system in different types of noisy channels ∗ C. J. Shan, J. B. Liu, W. W. Cheng, T. K. Liu, Y. X. Huang, and H. Li College of Physics and Electronic Science, Hubei Normal University, Huangshi 435002, China (Dated: August 27, 2008) Abstract In this paper, we study entanglement dynamics of a two-qubit extende...

ar X iv : 0 70 9 . 14 24 v 1 [ qu an t - ph ] 1 0 Se p 20 07 Gauss sum factorization with cold atoms

The Shor algorithm [1] to factor numbers and its NMRimplementation [2] have propelled the field of quantum computation [3]. Recently a different factorization scheme [4] taking advantage of the periodicity properties of Gauss sums [5] has been proposed [6] and verified by two NMR-experiments [7, 8] and one experiment based on short laser pulses [9]. In the present paper we report the first impl...

ar X iv : 1 40 3 . 36 47 v 1 [ qu an t - ph ] 1 4 M ar 2 01 4 Heisenberg Limit Superradiant Super - resolving Metrology

We propose a superradiant metrology scheme to achieve Heisenberg limit super-resolving displacement measurement by encoding multiple light momenta into a three-level atomic ensemble. We use 2N coherent pulses to prepare a single excitation superradiant state in a superposition of two timed Dicke states that are 4N light momenta apart in the momentum space. The phase difference between these two...

ar X iv : q ua nt - p h / 05 09 08 5 v 1 1 3 Se p 20 05 Improving the purity of one - and two - qubit gates by AC fields

We investigate the influence of AC driving fields on the coherence properties of one-and two-qubit gate operations. In both cases, we find that for suitable driving parameters, the gate purity improves significantly. A mapping of the time-dependent system-bath model to an effective static model provides analytical results. The resulting purity loss compares favorably with numerical results.

ar X iv : 0 80 1 . 48 21 v 2 [ he p - ph ] 2 8 Fe b 20 08 X ( 1835 ) and η ( 1760 ) observed by BES Collaboration