Efficient Spintronic THz Emitters Without External Magnetic Field

TL;DR

This paper demonstrates stable, efficient spintronic THz emitters that operate without external magnetic fields, achieved through oblique angle deposition to enhance magnetic anisotropy, promising practical applications in future THz technologies.

Contribution

It introduces a method to create field-free spintronic THz emitters with stable performance using oblique angle deposition to enhance magnetic anisotropy.

Findings

THz emission remains stable with or without external magnetic field

Oblique angle deposition enhances uniaxial magnetic anisotropy

Potential for practical, field-free THz emitters

Abstract

We investigate the performance of state-of-the-art spintronic THz emitters (W or Ta)/CoFeB/Pt with non-magnetic underlayer deposited using oblique angle deposition. The THz emission amplitude in the presence or absence of an external magnetic field remains the same and remarkably stable over time. This stability is attributed to the enhanced uniaxial magnetic anisotropy in the ferromagnetic layer, achieved by oblique angle deposition of the underlying non-magnetic layer. Our findings could be used for the development of practical field-free emitters of linearly polarized THz radiation, potentially enabling novel applications in future THz technologies.