We show that a variant of the one-way model where one only allows X and Y one qubit measurements is approximately universal.

The Pauli channel acting on 2 2 matrices is generalized to an n-level quantum system. When the full matrix algebraMn is decomposed into pairwise complementary subalgebras, then trace-preserving linear mappingsMn !Mn are constructed such that the restriction to the subalgebras are depolarizing channels. The result is the necessary and su cient condition of complete positivity. The main examples ...

In this paper the Levy-Leblond procedure for linearizing the Schrödinger equation to obtain the Pauli equation for one particle is generalized to obtain an N -particle equation with spin. This is achieved by using the more universal matrix factorization, GG̃ = |G|I = (−K)lI. Here the square matrix G is linear in the total energy E and all momenta, G̃ is the matrix adjoint of G, I is the identity ...

Improved model independent upper bounds on the weak transition form factors are derived using inclusive sum rules. Comparison of the new bounds with the old ones is made for the form factors hA1 and hV in B → D decays. [email protected] 1 A set of model independent bounds has been derived to provide a restriction on the shape of weak transition form factors [1–3]. They have been extensive...

The supersymmetry of the electron in both the nonstationary magnetic and electric fields in a two-dimensional case is studied. The supercharges which are the integrals of motion and their algebra are established. Using the obtained algebra the solutions of nonstationary Pauli equation are generated. PACS number(s): 03.65.-w; 11.30.Pb

Employing the fact that the geometry of the N -qubit (N ≥ 2) Pauli group is embodied in the structure of the symplectic polar space W(2N − 1, 2) and using properties of the Lagrangian Grassmannian LGr(N, 2N) defined over the smallest Galois field, it is demonstrated that there exists a bijection between the set of maximum sets of mutually commuting elements of the N -qubit Pauli group and a cer...