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Title: Parametric excitation in a magnetic tunnel junction-based spin torque oscillator

Using microwave current injection at room temperature, we demonstrate parametric excitation of a magnetic tunnel junction (MTJ)-based spin-torque oscillator (STO). Parametric excitation is observed for currents below the auto-oscillation threshold, when the microwave current frequency f{sub e} is twice the STO free-running frequency f{sub 0}. Above threshold, the MTJ becomes parametrically synchronized. In the synchronized state, the STO exhibits an integrated power up to 5 times higher and a linewidth reduction of two orders of magnitude, compared to free-running conditions. We also show that the parametric synchronization favors single mode oscillations in the case of multimode excitation.
Authors:
;  [1] ;  [1] ;  [2] ;  [1] ;  [3]
  1. Department of Physics, University of Gothenburg, 412 96 Gothenburg (Sweden)
  2. (Sweden)
  3. (India)
Publication Date:
OSTI Identifier:
22283303
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 104; Journal Issue: 5; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; COMPARATIVE EVALUATIONS; ELECTRIC CURRENTS; EXCITATION; MAGNETISM; MICROWAVE RADIATION; OSCILLATION MODES; OSCILLATIONS; OSCILLATORS; SPIN; SYNCHRONIZATION; TEMPERATURE RANGE 0273-0400 K; TORQUE; TUNNEL EFFECT