Slow Magnetic Relaxation of Ni(III) Complexes toward Molecular Spin Qubits

• Published in: European journal of inorganic chemistry Vol. 26; no. 19
• Main Authors: Toshima, Keiga, Sato, Tetsu, Horii, Yoji, Sato, Kazunobu, Sugisaki, Kenji, Breedlove, B. K., Takaishi, Shinya, Li, Zhao‐Yang, Yamashita, Masahiro
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 03.07.2023
• Subjects: Coordination compounds; Electron paramagnetic resonance; Electron spin; Inorganic chemistry; Magnetic induction; Magnetic materials; Magnetic properties; Magnetic relaxation; Nickel; Nickel compounds; Planar structures; Qubits (quantum computing); Spin qubits; Spin relaxation; Spin resonance; Structure elucidation; Transition metal compounds
• ISSN: 1434-1948; 1099-0682
• DOI: 10.1002/ejic.202300125

Molecule‐based magnetic materials are promising candidates for molecular spin qubits, which utilize spin relaxation behavior. Various kinds of transition metal complexes with S=1/2 have been reported to act as spin qubits with long spin‐spin relaxation times (T2). However, the spin qubit properties of low‐spin Ni(III) complexes are not as well known since Ni(III) compounds are often unstable. We report here the slow magnetic relaxation behavior and T2 values for three kinds of low‐spin Ni(III) based complexes with S=1/2 under magnetically diluted conditions. [Ni(cyclam)X2]Y (cyclam=1,4,8,11‐tetraazacyclotetradecane) with octahedral structures and [Ni(mnt)2]− (mnt=maleonitriledithiolate) with a square‐planar structure underwent slow magnetic relaxations in the presence of a dc magnetic bias field. From electron spin resonance (ESR) spectroscopy, the Ni(III) complexes exhibited observable T2, indicating that Ni(III) complexes are promising candidates for use as molecule‐based spin qubits. Ni(III) complexes exhibited slow magnetic relaxation that attributed to the spin‐lattice relaxations, as well as the spin‐spin relaxations with observable T2 values, indicating that Ni(III) complexes are promising candidates for spin qubits.