# Quantum noise in the spin transfer torque effect

## TL;DR

This paper uses the Keldysh technique to analyze quantum noise in spin transfer torque effects, highlighting how noise originates from spin conductance in open quantum systems.

## Contribution

It introduces a quantum microscopic description of noise in spin transfer torque using the Keldysh formalism, linking noise sources to spin conductance effects.

## Key findings

- Noise arises from both field-like and damping-like terms.
- The Keldysh approach reveals microscopic origins of quantum noise.
- Open quantum system framework clarifies spin-current interactions.

## Abstract

Describing the microscopic details of the interaction of magnets and spin-polarized currents is key to achieve control of such systems at the microscopic level. Here we discuss a description based on the Keldysh technique, casting the problem in the language of open quantum systems. We reveal the origin of noise in the presence of both field-like and damping like terms in the equation of motion arising from spin conductance.