Intriguing Hysteresis Dynamics in Ultrafast Photo‐Induced Magnetization. Issue 3 (20th September 2019)

• Record Type: Journal Article
• Authors: Shim, Je-Ho; Kim, Chul-Hoon; Piao, Hong-Guang; Lee, Sang-Hyuk; Lee, Kyung Min; Jeong, Jong-Ryul; Park, Seung-Young; Choi, Yeon Suk; Kim, Dong Eon; Kim, Dong-Hyun
• Is Part Of: Physica status solidi. Volume 257:Issue 3(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2019-09-20
• Subjects: spin dynamics -- time-resolved magneto-optical Kerr effect -- photoinduced magnetization -- magnetic hysteresis; Solid state physics -- Periodicals; Solids -- Periodicals; Atomic structure -- Periodicals; 530.41
• DOI: 10.1002/pssb.201900307
• Languages: English
• ISSNs: 0370-1972

Abstract

Abstract : Time‐resolved magneto‐optical Kerr effect measurement is carried out to determine ultrafast hysteresis behavior during a photo‐induced demagnetization/remagnetization process for Co/Pt ferromagnetic multilayers. Due to the stroboscopic measurement scheme, hysteresis curve measured by a pump–probe technique exhibits an irreversible behavior, repeatedly reset to a metastable hysteresis state at each stroboscopic measurement, observed as the reduction of the coercivity. It is demonstrated that the stroboscopically measured hysteresis and the coercivity could be a stable parameter in describing the ultrafast photo‐induced spin dynamics for both reversible and irreversible behaviors. Moreover, it is found that an unusual coercivity behavior exists together with a nontrivial magnetization change under external fields comparable to the coercivity of the sample. Abstract : Ultrafast hysteresis behavior of Co/Pt multilayer is measured by time‐resolved magneto‐optical Kerr effect. Coercivity reduction is observed due to irreversible behavior in pump–probe stroboscopic measurement. The unusual coercivity behavior is consistent with the estimation based on a relation between hysteresis area and saturation. It is concluded that the coercivity behavior can match well with ultrafast photoinduced spin dynamics.