Can a non-ideal metal ferromagnet inject spin into a semiconductor with 100% efficiency without a tunnel barrier?

Details Can a non-ideal metal ferromagnet inject spin into a semiconductor with 100% efficiency without a tunnel barrier? Can a non-ideal metal ferromagnet inject spin into a semiconductor with 100% efficiency without a tunnel barrier?

2006-02-14

arxiv.org/abs/cond-mat/0602335v1

Physics

Condensed Matter

Mesoscale and Nanoscale Physics

Scientific paper

Current understanding of spin injection tells us that a metal ferromagnet can inject spin into a semiconductor with 100% efficiency if either the ferromagnet is an ideal half metal with 100% spin polarization, or there exists a suitable tunnel barrier at the interface. In this paper, we show that, at absolute zero temperature, 100% spin injection efficiency from a non-ideal metal ferromagnet into a semiconductor quantum wire can be reached at certain injection energies, without a tunnel barrier, provided there is an axial magnetic field along the direction of current flow as well as a spin orbit interaction in the semiconductor. At these injection energies, spin is injected only from the majority spin band of the ferromagnetic contact, resulting in 100% spin injection efficiency. This happens because of the presence of antiresonances in the transmission coefficient of the minority spins when their incident energies coincide with Zeeman energy states in the quantum wire. At absolute zero and below a critical value of the axial magnetic field, there are two distinct Zeeman energy states and therefore two injection energies at which ideal spin filtering is possible; above the critical magnetic field there is only one such injection energy. The spin injection efficiency rapidly decreases as the temperature increases. The rate of decrease is slower when the magnetic field is above the critical value. The appropriate choice of semiconductor materials and structures necessary to maintain a large spin injection efficiency at elevated temperatures is discussed.

Affiliated with

Also associated with

No associations

Rating

Can a non-ideal metal ferromagnet inject spin into a semiconductor with 100% efficiency without a tunnel barrier? does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Can a non-ideal metal ferromagnet inject spin into a semiconductor with 100% efficiency without a tunnel barrier?, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Can a non-ideal metal ferromagnet inject spin into a semiconductor with 100% efficiency without a tunnel barrier? will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-568025