# Search results for: Willi-Hans Steeb

International Journal of Theoretical Physics > 2019 > 58 > 5 > 1470-1481

*n*×

*n*matrices over ℂ and their corresponding Fermi-quadratic forms. The properties of these operators are studied with respect to the properties of the underlying matrices. It is well known that these Fermi-quadratic forms have a faithful matrix representation. The purpose of this article is to investigate the (un)faithful representation of the matrix algebra by its Fermi-quadratic...

Quantum Information Processing > 2014 > 13 > 2 > 299-308

Linear Algebra and Its Applications > 2013 > 439 > 12 > 4023-4031

Open Physics > 2009 > 7 > 4 > 854-859

Open Physics > 2009 > 7 > 4 > 854-859

Central European Journal of Physics > 2009 > 7 > 4 > 854-859

*Ĥ*

_{ N }in finite dimensional Hilbert spaces $$ \mathbb{C}^{2^N } $$ . We show that the eigenstates of

*Ĥ*

_{ N }are fully entangled for

*N*even. We also calculate the unitary operator

*U*

_{ N }(

*t*) = exp(—

*Ĥ*

_{ N }

*t*/

*ħ*) for the time evolution and show that unentangled states can be transformed into entangled states using this operator. We also investigate energy...

International Journal of Theoretical Physics > 2006 > 45 > 5 > 924-932

International Journal of Theoretical Physics > 2005 > 44 > 9 > 1617-1620

International Journal of Theoretical Physics > 2004 > 43 > 11 > 2207-2213

**C**

^{2}⊗ l

_{2}(

**N**). An explicit expression is given for the entanglement. We consider number states, coherent states and macroscopic quantum superposition states in the product system. Explicit formulas for the entanglement are also given in each of these cases.

International Journal of Theoretical Physics > 2004 > 43 > 2 > 341-347

**C**

^{2}⊗

**C**

^{2}to be entangled to find when states evolving under the two-point Hubbard model become entangled. We also investigate the connection of entanglement and discrete symmetries of...

International Journal of Theoretical Physics > 2003 > 42 > 12 > 2847-2853

**C**

^{ N }⊗

**C**

^{ N }starting from a unitary matrix and show that they form an orthonormal basis in this space.

International Journal of Theoretical Physics > 2000 > 39 > 12 > 2755-2760

**C**

^{9}to be entangled and a solution to the corresponding factorization problem if thisis not the case.