Electric Field Modulation of Spin Accumulation in Nb-doped SrTiO3 with Ni/AlOx Spin Injection Contacts

We demonstrate an electric field control of spin lifetime at room temperature, across a semiconducting interface of Nb:STO using Ni/AlOx as spin injection contacts. We achieve this by a careful tailoring of the potential landscape in Nb:STO, driven by the strong response of the intrinsically large dielectric permittivity in STO to electric fields. The built-in electric field at the Schottky interface with Nb: STO tunes the intrinsic Rashba spin-orbit fields leading to a bias dependence of the spin lifetime in Nb:STO. Such an electric field driven modulation of spin accumulation has not been reported earlier using conventional semiconductors. This not only underpins the necessity of a careful design of the spin injection contacts but also establishes the importance of Nb:STO as a rich platform for exploring spin-orbit driven phenomena in complex oxide based spintronic devices.

[1]  T. Kimura,et al.  Experimental evidence of cubic Rashba effect in an inversion-symmetric oxide. , 2012, Physical review letters.

[2]  Y. Baba,et al.  Qualitative study of temperature-dependent spin signals in n-Ge-based lateral devices with Fe3Si/n+-Ge Schottky-tunnel contacts , 2013 .

[3]  K. Rana,et al.  Electrical transport across Au/Nb:SrTiO3 Schottky interface with different Nb doping , 2012, 1302.2096.

[4]  G. Schmidt,et al.  Fundamental obstacle for electrical spin injection from a ferromagnetic metal into a diffusive semiconductor , 1999, cond-mat/9911014.

[5]  Saroj P. Dash,et al.  Electrical creation of spin polarization in silicon at room temperature , 2009, Nature.

[6]  Byounghak Lee,et al.  Theory of t 2g electron-gas Rashba interactions , 2013, 1301.2784.

[7]  J. J. A. Baselmans,et al.  Electrical detection of spin precession in a metallic mesoscopic spin valve , 2002, Nature.

[8]  Raymond J. E. Hueting,et al.  Electrostatic analysis of n-doped SrTiO3 metal-insulator-semiconductor systems , 2015 .

[9]  André Dankert,et al.  Electric field effects on spin accumulation in Nb-doped SrTiO3 using tunable spin injection contacts at room temperature , 2014 .

[10]  A M Kamerbeek,et al.  Electric Field Control of Spin Lifetimes in Nb-SrTiO_{3} by Spin-Orbit Fields. , 2015, Physical review letters.

[11]  H. Hasegawa,et al.  Electrical properties of Au/Nb-doped-SrTiO3 contact , 1991 .

[12]  C. Leighton,et al.  Electronic transport in doped SrTiO3: Conduction mechanisms and potential applications , 2010 .

[13]  M. Gabay,et al.  Tunable Rashba spin-orbit interaction at oxide interfaces. , 2009, Physical review letters.

[14]  George Kioseoglou,et al.  Electrical spin-injection into silicon from a ferromagnetic metal/tunnel barrier contact , 2007 .

[15]  Jeremy Levy,et al.  Nanoscale Phenomena in Oxide Heterostructures , 2014 .

[16]  A. Fert,et al.  Enhancement of the spin accumulation at the interface between a spin-polarized tunnel junction and a semiconductor. , 2008, Physical review letters.

[17]  C. Mead,et al.  Permittivity of Strontium Titanate , 1972 .

[18]  Tetsuya Yamamoto,et al.  Fabrication and characterization of Ba1−xKxBiO3/Nb-doped SrTiO3 all-oxide-type Schottky junctions , 1997 .

[19]  Horst Rogalla,et al.  Quasi-ideal strontium titanate crystal surfaces through formation of strontium hydroxide , 1998 .

[20]  S. Baek,et al.  Abnormal bias dependence of magnetoresistance in CoFeB/MgO/Si spin-injection tunnel contacts , 2015 .

[21]  S. Parkin,et al.  Spin injection and detection in lanthanum- and niobium-doped SrTiO3 using the Hanle technique , 2013, Nature Communications.

[22]  A. Lemaître,et al.  Spin precession and inverted Hanle effect in a semiconductor near a finite-roughness ferromagnetic interface , 2011, 1101.1691.

[23]  S. Sarma,et al.  Spintronics: Fundamentals and applications , 2004, cond-mat/0405528.

[24]  C. Adelmann,et al.  Electrical detection of spin transport in lateral ferromagnet–semiconductor devices , 2006, cond-mat/0701021.