Title: Unifying femtosecond and picosecond single-pulse magnetic switching in Gd-Fe-Co

Abstract

Many questions are still open regarding the physical mechanisms behind the magnetic switching in Gd-Fe-Co alloys by single optical pulses. Phenomenological models suggest a femtosecond scale exchange relaxation between sublattice magnetization as the driving mechanism for switching. The recent observation of thermally induced switching in Gd-Fe-Co by using both several picosecond optical laser pulse as well as electric current pulses has questioned this previous understanding. This has raised the question of whether or not the same switching mechanics are acting at the femtosecond and picosecond scales. In this work, we aim at filling this gap in the understanding of the switching mechanisms behind thermal single-pulse switching. To that end, we have studied experimentally thermal single-pulse switching in Gd-Fe-Co alloys, for a wide range of system parameters, such as composition, laser power, and pulse duration. We provide a quantitative description of the switching dynamics using atomistic spin dynamics methods with excellent agreement between the model and our experiments across a wide range of parameters and timescales, ranging from femtoseconds to picoseconds. Furthermore, we find distinct element-specific damping parameters as a key ingredient for switching with long picosecond pulses and argue that switching with pulse durations as long as 15 ps ismore » possible due to a low damping constant of Gd. Our findings can be easily extended to speed up dynamics in other contexts where ferrimagnetic Gd-Fe-Co alloys have been already demonstrated to show fast and energy-efficient processes, e.g., domain-wall motion in a track and spin-orbit torque switching in spintronics devices.« less

Authors:

Jakobs, F. ^[1]; Ostler, T. A. ^[2]; Lambert, C. -H. ^[3]; Yang, Y. ^[4]; Salahuddin, S. ^[5]; Wilson, R. B. ^[6]; Gorchon, J.  ^[5];

• Search DOE PAGES for author "Gorchon, J."
• Search DOE PAGES for ORCID "0000-0003-2578-0835"

Bokor, J.  ^[5];

• Search DOE PAGES for author "Bokor, J."
• Search DOE PAGES for ORCID "0000-0002-4541-0156"

Atxitia, U.  ^[1]

• Search DOE PAGES for author "Atxitia, U."
• Search DOE PAGES for ORCID "0000-0002-2871-5644"

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+ Show Author Affiliations

1. Freie Univ., Berlin (Germany). Dahlem Center for Complex Quantum Systems and Fachbereich Physik
2. Univ. of Liege, (Belgium). Dept. de Physique; Sheffield Hallam Univ. (United Kingdom). College of Business, Technology and Engineering
3. Univ. of California, Berkeley, CA (United States). Dept. of Electrical Engineering and Computer Sciences
4. Univ. of California, Berkeley, CA (United States). Dept. of Materials Science and Engineering
5. Univ. of California, Berkeley, CA (United States). Dept. of Electrical Engineering and Computer Sciences; Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
6. Univ. of California, Riverside, CA (United States). Dept. of Mechanical Engineering and Materials Science and Engineering Program

Publication Date:

Mon Mar 15 00:00:00 EDT 2021

Research Org.:

Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES). Materials Sciences & Engineering Division; German Research Foundation (DFG); UK EPSRC; National Science Foundation (NSF)

OSTI Identifier:

1822404

Grant/Contract Number:  

AC02-05CH11231; SFB/TRR-227; EP/T027916/1

Resource Type:

Accepted Manuscript

Journal Name:

Physical Review. B

Additional Journal Information:

Journal Volume: 103; Journal Issue: 10; Journal ID: ISSN 2469-9950

Publisher:

American Physical Society (APS)

Country of Publication:

United States

Language:

English

Subject:

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; demagnetization; magnetic interactions; magnetic order; magnetism; spin dynamics; ultrafast magnetic effects