Spin driven emergent antiferromagnetism and metal insulator transition in nanoscale p-Si

Abstract

The entanglement of the charge, spin and orbital degrees of freedom can give rise to emergent behavior especially in thin films, surfaces and interfaces. Often, materials that exhibit those properties require large spin orbit coupling. We hypothesize that the emergent behavior can also occur due to spin, electron and phonon interactions in widely studied simple materials such as Si. That is, large intrinsic spin-orbit coupling is not an essential requirement for emergent behavior. The central hypothesis is that when one of the specimen dimensions is of the same order (or smaller) as the spin diffusion length, then non-equilibrium spin accumulation due to spin injection or spin-Hall effect (SHE) will lead to emergent phase transformations in the non-ferromagnetic semiconductors. In this experimental work, we report spin mediated emergent antiferromagnetism and metal insulator transition in a Pd (1 nm)/Ni81Fe19 (25 nm)/MgO (1 nm)/p-Si (~400 nm) thin film specimen. The spin-Hall effect in p-Si, observed through Rashba spin-orbit coupling mediated spin-Hall magnetoresistance behavior, is proposed to cause the spin accumulation and resulting emergent behavior. The phase transition is discovered from the diverging behavior in longitudinal third harmonic voltage, which is related to the thermal conductivity and heat capacity.

34 pages, Physica Status Solidi B- Physics, 2017

References in corpus (6)

• Emergent Phenomena Induced by Spin-Orbit Coupling at Surfaces and Interfaces
• Theory of spin Hall magnetoresistance
• Metal-insulator transition in two-dimensional electron systems
• Tunneling anisotropic magnetoresistance and spin-orbit coupling in Fe/GaAs/Au tunnel junctions
• Simultaneous detection of the spin-Hall magnetoresistance and the spin-Seebeck effect in Platinum and Tantalum on Yttrium Iron Garnet
• Hole spin resonance and spin-orbit coupling in a silicon metal-oxide-semiconductor field-effect transistor

Cited by in corpus (5)

• Large spin-Hall effect in Si at room temperature
• Flexoelectronic doping of the degenerate silicon and the correlated electron behavior
• Oscillatory Hall effect from magnetoelectronic coupling in flexoelectronic silicon
• Evidence of magnetoelectronic electromagnon mediated transport in flexoelectronic heterostructures
• Interlayer charge transfer from contact electrification in conducting micro and nanoscale thin film heterostructures