Chirality-induced spin-selectivity based spin lasers

• Applicant: Professor Dr.-Ing. Nils Christopher Gerhardt
• Subject Area: Electronic Semiconductors, Components and Circuits, Integrated Systems, Sensor Technology, Theoretical Electrical Engineering ; Communication Technology and Networks, High-Frequency Technology and Photonic Systems, Signal Processing and Machine Learning for Information Technology
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 545617027

Spin lasers have attracted intensive interest in the last two decades due to the strong potential to reform the actual optic telecom technology using circular polarization modulation. Spin laser possesses two unique advantages. First, even with low electron spin-polarization injection (2-3%), the spin laser may emit light with almost full circular polarization, thus acting as a spin amplifier. The second advantage is the reduction of the threshold current by almost half of that of a “classical” laser. Spin laser functionality can be achieved by embedding a ferromagnetic injector in an optical cavity to inject spin carriers into a semiconductor gain medium. This is generally realized by a vertical cavity surface emitting laser (VCSEL) or vertical external cavity surface emitting laser (VECSEL). However, due to the optical absorption of the metal in the cavity, the spin V(E)CSEL structure design including the wavelength and the distance between surface and active region becomes very critical. In this project, we will explore a new type of spin injector with chiral organic-inorganic hybrid perovskite (OIHP). Owing to the chiral-induced spin selectivity (CISS), carriers passing through the OIHP layer can produce a high spin-polarization. The advantages of this kind of materials as spin injector for spin optoelectronic devices are 1) high-efficient spin injection efficiency (>80% with 30nm thickness); 2) optical transparency to the wavelength of V(E)CSEL with a bandgap around 2eV; 3) CISS polarization in perpendicular direction. The 3 objectives of this project are 1) Electrical assessment of spin injection in GaAs with CISS layer; 2) Developing spin-LED and photodiode with CISS injector; 3) Demonstration of spin VECSEL function with CISS injector. The success of this project will generate novel chiral spin optoelectronic devices based on OIHPs with great potential for various applications, such as quantum communication, optical information processing and biological science.

• DFG Programme: Research Grants
• International Connection: France
• Partner Organisation: Agence Nationale de la Recherche / The French National Research Agency
• Cooperation Partners: Professor Dr. Henri Jaffres; Yuan Lu, Ph.D.