한국광학회지 (Korean Journal of Optics and Photonics)

  • 제35권5호
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  • Pages.218-227
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  • 2024
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  • 1225-6285(pISSN)
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  • 2287-321X(eISSN)
한국광학회 (Optical Society of Korea)
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스핀 각 운동량을 이용한 테라헤르츠파 광원: 스핀트로닉 테라헤르츠 발생

Terahertz Light Source Using Spin Angular Momentum: Spintronic Terahertz Emission

  • 이규섭 (국립부경대학교 물리학과)
  • Kyusup Lee (Department of Physics, Pukyong National University)
  • 투고 : 2024.08.16
  • 심사 : 2024.09.24
  • 발행 : 2024.10.25
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초록

펨토초 레이저 펄스를 이용한 테이블 탑(table-top) 규모의 THz파 광원은 주로 전자가 가진 전하량의 시공간적인 변화를 기반으로 한다. 본 해설논문에서는 전자가 가진 스핀 각운동량이 THz파 발생에 기여하는 새로운 방식에 대해 소개한다. 우선 강자성체(ferromagnet)에서의 레이저 유도 스핀 전류 발생에 초점을 맞추어 나노미터 두께의 강자성체/비자성체 복합 박막에서의 고출력, 광대역, 편광 자유도 등 우수한 특성을 설명한다. 또한 나노미터 두께의 박막을 기반으로 반도체 결합 소자 개발, 대면적 광 소자 개발, 플렉시블 광 소자 개발 등의 다양한 응용 기술 연구를 소개한다. 이를 통해 스핀트로닉 THz파 발생 원리를 이해하고, 차세대 THz 광 소자로서 주목받고 있는 전자의 스핀을 활용한 다양한 응용 연구를 수행하는 데 도움을 주고자 한다.

The tabletop-scale terahertz (THz) light sources using femtosecond laser pulses are primarily based on spatiotemporal changes in electron charge. This review introduces a new scheme where the spin angular momentum of electrons contributes to THz wave generation. By focusing on laser-induced spin current generation in ferromagnets, we review the outstanding characteristics observed in nanometric ferromagnetic/nonmagnetic thin films, including high power, ultra-broadband, and polarization tunability. Additionally, research on various application technologies is introduced, including the development of devices combining semiconductors, large-area THz devices, and flexible THz devices, all based on nanoscale thin films. Through this, the principle of spintronic THz emission can be understood, contributing the advancement of various application studies utilizing electron spin as a next-generation THz optical device.

키워드

과제정보

정부(과학기술정보통신부)의 재원으로 한국연구재단의 지원을 받아 수행(Grant no. RS-2024-00454395); 2023년도 교육부의 재원으로 한국연구재단의 지원을 받는 지자체-대학 협력기반 지역혁신사업(Grant no. 2023RIS-007); 2023학년도 부경대학교의 지원을 받아 수행(202303670001).

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