A1 Journal article (refereed)
Spin Pumping and Torque Statistics in the Quantum Noise Limit (2017)

Virtanen, P., & Heikkilä, T. (2017). Spin Pumping and Torque Statistics in the Quantum Noise Limit. Physical Review Letters, 118(23), Article 237701. https://doi.org/10.1103/PhysRevLett.118.237701

JYU authors or editors

Publication details

All authors or editorsVirtanen, Pauli; Heikkilä, Tero

Journal or seriesPhysical Review Letters



Publication year2017


Issue number23

Article number237701

PublisherAmerican Physical Society

Publication countryUnited States

Publication languageEnglish


Publication open accessOther way freely accessible online

Publication channel open access

Publication is parallel published (JYX)https://jyx.jyu.fi/handle/123456789/54480

Web address where publication is availablehttps://arxiv.org/abs/1609.04619


We analyze the statistics of charge and energy currents and spin torque in a metallic nanomagnet coupled to a large magnetic metal via a tunnel contact. We derive a Keldysh action for the tunnel barrier, describing the stochastic currents in the presence of a magnetization precessing with the rate Ω. In contrast to some earlier approaches, our result is valid for an arbitrary ratio of ℏΩ/kBT. We illustrate the use of the action by deriving spintronic fluctuation relations, the quantum limit of pumped current noise, and consider the fluctuations in two specific cases: the situation with a stable precession of magnetization driven by spin transfer torque, and the torque-induced switching between the minima of a magnetic anisotropy. The quantum corrections are relevant when the precession rate exceeds the temperature T, i.e., for ℏΩ≳kBT.

Keywordsnanotechnologyquantum mechanicscomputational fluid dynamicsmagnetism

Free keywordsspin pumping; torque statistics; quantum noise limit

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Ministry reportingYes

Reporting Year2017

JUFO rating3

Last updated on 2024-11-05 at 17:06