ar X iv : 0 71 0 . 18 02 v 2 [ qu an t - ph ] 1 2 N ov 2 00 7 A complex periodic QES potential and exceptional points

ar X iv : 0 71 0 . 34 25 v 2 [ qu an t - ph ] 1 4 N ov 2 00 7 Properties of the residual entanglement for n - qubits 1

X iv :0 71 0. 34 25 v2 [ qu an tph ] 1 4 N ov 2 00 7 Properties of the residual entanglement for n-qubits Dafa Li, Xiangrong Li, Hongtao Huang, Xinxin Li a Dept of mathematical sciences, Tsinghua University, Beijing 100084 CHINA b Department of Mathematics, University of California, Irvine, CA 92697-3875, USA c Electrical Engineering and Computer Science Department University of Michigan, Ann A...

ar X iv : 0 71 1 . 35 78 v 1 [ qu an t - ph ] 2 2 N ov 2 00 7 A formula for the spectral projection of the time operator

In this paper, we study the one-level Friedrichs model with using the quantum time super-operator that predicts the excited state decay inside the continuum. Its survival probability in long time limit is an algebraically decreasing function and an exponentially decreasing multiplied by the oscillating functions.

ar X iv : 0 71 1 . 32 82 v 1 [ he p - ph ] 2 1 N ov 2 00 7 Study of Pure Annihilation Decays B d , s → D 0 D 0

With heavy quark limit and hierarchy approximation λ QCD ≪ m D ≪ m B , we analyze the

ar X iv : 0 71 0 . 49 47 v 2 [ he p - ph ] 2 3 N ov 2 00 7 International scoping study of a future Neutrino Factory and super - beam facility

O ct 2 00 7 A complex periodic QES potential and exceptional points

We show that the complex PT -symmetric periodic potential V (x) = −(iξ sin 2x+ N)2, where ξ is real and N is a positive integer, is quasi-exactly solvable. For odd values of N ≥ 3, it may lead to exceptional points depending upon the strength of the coupling parameter ξ. The corresponding Schrödinger equation is also shown to go over to the Mathieu equation asymptotically. The limiting value of...