Kazi M. Alam

Suppression of spin relaxation in rubrene nanowire spin valves

We report spin valve measurements performed on vertically oriented array of amorphous rubrene (5,6,11,12-tetraphenylnaphthacene) nanowires. Compared to previously reported rubrene thin-film spin valves, rubrene nanowires exhibit significant suppression of spin relaxation. Our results indicate spin-orbit interaction to be the dominant mechanism and are consistent with recent theoretical works, which suggest spin admixture parameter as a crucial ingredient in determining spin relaxation length.

High Density Integration of Carbon Nanotube Spin Valves

In this work we report fabrication and characterization of short-channel multi-walled carbon nanotube (MWCNT) based spin valves. These devices are embedded in hexagonally ordered nanopores in an anodic alumina template and show spin relaxation length of 0.28 μm at 8K.

High-field magnetoresistance effects and temperature-dependent spin relaxation in rubrene nanowire spin valves

In this work we discuss the high-field magnetoresistance effects and temperature-dependent spin relaxation in rubrene nanowire spin valves. Rubrene thin film spin valves have been studied by several groups in the past since this material can potentially offer long spin relaxation length (Ls). However, the Ls values reported so far have been low, typically ~10 nm at low temperatures (~10K). Recently we have reported a vertical spin valve device using rubrene spacer, in which rubrene is patterned in a nanowire array geometry. Such patterning leads to significant suppression of spin relaxation and we have reported spin relaxation length of ~47 nm at ~10K in rubrene nanowires. In this work we present the high field magnetoresistance measurements performed on rubrene nanowires and discuss the possible origins of these effects. Further, we discuss possible origin of the observed temperature-dependence of spin relaxation length.