Related papers: All-Electric Quantum Point Contact Spin Valve

This paper has been withdrawn due to an error in section 3.

This paper has been withdrawn by the authors. We have discovered an error in the evaluation of the diagram, which invalidates our conclusion.

This paper has been withdrawn by the author.

This paper has been withdrawn by the author due to some problems.

This paper has been withdrawn by the author due to a gap in the proof of the main result.

This paper has been withdrawn by the author due to a crucial error in eq.59. I apologize for the inconveniences.

This paper has been withdrawn by the author because of copyright reasons.

This paper has been withdrawn by the author(s),

The paper has been withdrawn.

This paper has been withdrawn by the authors.

This paper has been withdrawn by the author, since the author does not have enough time to answer every questions on this result.

The article is taken out.

This paper has been withdrawn by the author(s). Please see arXiv:0711.3910 for revision.

This paper has been withdrawn by the author(s), due a crucial error on the entanglement of $\Gamma$ registers.

This paper has been withdrawn and merged with hep-ph/0611379 for publication in Physical Review D

This paper has been withdrawn by the author due to a serious errors in the calculations.

This paper has been withdrawn by the author due to some problems. Please contact me.

This paper has been withdrawn by the author, due to a crucial error in page 5.

This paper has been withdrawn by the author due to an erro thereon line -2 of page 4.

This paper has been withdrawn due to fundamental errors.