Temperature dependence of microwave voltage emission associated to spin-transfer induced vortex oscillation in magnetic tunnel junction

TL;DR

This study investigates how temperature affects microwave voltage emission from spin-transfer vortex oscillators in magnetic tunnel junctions, revealing temperature-dependent linewidth behavior and limits at low temperatures.

Contribution

It provides new insights into the temperature dependence of vortex-based nano-oscillators, highlighting linear linewidth reduction and a low-temperature linewidth limit.

Findings

Large output power and good coherence in emitted signals

Linearity in linewidth decrease with temperature reduction

Existence of a linewidth bottom limit at low temperatures

Abstract

The temperature dependence of a vortex-based nano-oscillator induced by spin transfer torque (STVO) in magnetic tunnel junctions (MTJ) is considered. We obtain emitted signals with large output power and good signal coherence. Due to the reduced non-linearities compared to the uniform magnetization case, we first observe a linear decrease of linewidth with decreasing temperature. However, this expected behavior no longer applies at lower temperature and a bottom limit of the linewidth is measured.