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


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Publication details

All authors or editorsVirtanen, Pauli; Heikkilä, Tero

Journal or seriesPhysical Review Letters

ISSN0031-9007

eISSN1079-7114

Publication year2017

Volume118

Issue number23

Article number237701

PublisherAmerican Physical Society

Publication countryUnited States

Publication languageEnglish

DOIhttps://doi.org/10.1103/PhysRevLett.118.237701

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


Abstract

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