Mode-hopping mechanism generating colored noise in a magnetic tunnel junction based spin torque oscillator
- Indian Inst. of Technology (IIT), New Delhi (India)
- Univ. of Gothenburg (Sweden). Dept. of Physics
- Argonne National Lab. (ANL), Argonne, IL (United States). Materials Science Division
- Univ. of Gothenburg (Sweden). Dept. of Physics; KTH Royal Inst. of Technology, Kista (Sweden). School of Information and Communication Technology (ICT)
- Indian Inst. of Technology (IIT), New Delhi (India); Univ. of Gothenburg (Sweden). Dept. of Physics
The frequency noise spectrum of a magnetic tunnel junction (MTJ) based spin torque oscillator (STO) is examined where multiple modes and mode-hopping events are observed. The frequency noise spectrum is found to consist of both white noise and 1/f frequency noise. Here, we find a systematic and similar dependence of both white noise and 1/f frequency noise on bias current and the relative angle between the reference and free layers, which changes the effective damping and hence the mode-hopping behavior in this system. The frequency at which the 1/f frequency noise changes to white noise increases as the free layer is aligned away from the anti-parallel orientation w.r.t the reference layer. Lastly, these results indicate that the origin of 1/f frequency noise is related to mode-hopping which produces both white noise as well as 1/f frequency noise similar to the case of ring lasers.
- Research Organization:
- Argonne National Laboratory (ANL), Argonne, IL (United States)
- Sponsoring Organization:
- Swedish Foundation for Strategic Research (SSF); Swedish Research Council (VR); USDOE Office of Science (SC), Basic Energy Sciences (BES)
- Grant/Contract Number:
- AC02-06CH11357
- OSTI ID:
- 1357043
- Journal Information:
- Applied Physics Letters, Vol. 105, Issue 13; ISSN 0003-6951
- Publisher:
- American Institute of Physics (AIP)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
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