Optical Response in Spintronic Poisson Bolometers

TL;DR

This paper experimentally investigates the optical response of a room-temperature spintronic Poisson bolometer based on magnetic tunnel junctions, demonstrating Poissonian behavior and significant response modulation under illumination for infrared detection.

Contribution

It provides the first experimental analysis of the statistical optical response of spintronic Poisson bolometers, highlighting their potential for high-speed, high-sensitivity infrared detection.

Findings

Poissonian behavior of magnetic state transitions observed

Transition rates increase by 153% under illumination

Interarrival times decrease by 70% with light

Abstract

Analog bolometers based on temperature-dependent phase-transition materials such as vanadium oxide (VOx) and barium titanate (BTO) represent the state of the art in uncooled infrared detectors. Recently, the first room-temperature spintronic Poisson bolometer based on magnetic tunnel junctions (MTJs) was proposed and demonstrated as a promising infrared detector. Unlike conventional bolometers, the spintronic Poisson bolometer operates in a probabilistic regime dominated by Poissonian noise, where the response is governed by resistance fluctuations arising from thermally activated magnetization transitions. Spontaneous transitions between two metastable magnetic states occur even in the absence of incident light, and the transition probability increases under illumination. In this work, we experimentally study the statistical properties of the optical response of the spintronic Poisson bolometer under illumination. We demonstrate that transitions in spintronic Poisson bolometers, both in the absence and presence of light, exhibit Poissonian behavior, with transition rates and interarrival times modulated by incident radiation. Under illumination, we observe a 153% increase in the count rate accompanied by a 70% reduction in interarrival time. These results establish spintronic Poisson bolometers as a promising platform for probabilistic, high-speed, and high-sensitivity infrared detection at room temperature.