Spin-Orbit Coupled Molecular Quantum Magnetism Realized in Inorganic Solid

Published

September 21, 2016

Author(s)

Sang-Youn Park, S.-H. Do, K.-Y. Choi, J.-H. Kang, Dongjin Jang, B. Schmidt, Manuel Brando, B.-H. Kim, D.-H. Kim, Nicholas Butch, Seongsu Lee, Sungdae Ji

Abstract

The molecular magnetism, representing an isolated spin state, is of particular interest due to characteristics of quantum magnetism with quantum tunneling phenomena underlying qubits or molecular spintronics for the quantum information devices. Such quantum magnetism has been realized in magnetic metal-organic molecular systems, the so-called molecular magnets. Here, we report the molecular quantum magnetism realized in an inorganic solid Ba₃Yb₂Zn₅O₁₁, which forms alternating three dimensional arrays of small and large tetrahedrons consisting of four spin-orbit coupled pseudospin-1/2 Yb³⁺ ions. The observed magnetization represents the magnetic quantum values of the isolated tetrahedron with effectively a total(pseudo)spin S_eff =2. Inelastic neutron scattering (INS) results with an external magnetic field reveals that extraordinarily large Dzyaloshinsky-Moriya (DM) interaction originating from strong spin-orbit coupling in Yb pseudospin is a key ingredient to explain magnetic excitations of the molecular spin S_eff = 2 in addition to Heisenberg exchange interaction and Zeeman effect. The DM interaction allows a non-adiabatic quantum transition between avoided crossing energy levels, the so-called Landau-Zener transition, and also results in unexpected magnetic behaviors in conventional molecular magnets. Our finding not only opens a possibility for qubit device applications with the benefit of regularity in the inorganic solid but also provides a playground to study the crossover of quantum magnetism with strong spin-orbit coupling from isolated to geometrically frustrated magnetic systems by manipulating the inter-molecular distance.

Citation

Nature Communications

Volume

7

Pub Type

Journals

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Keywords

frustrated magnetism

Citation

Park, S. , Do, S. , Choi, K. , Kang, J. , Jang, D. , Schmidt, B. , Brando, M. , Kim, B. , Kim, D. , Butch, N. , Lee, S. and Ji, S. (2016), Spin-Orbit Coupled Molecular Quantum Magnetism Realized in Inorganic Solid, Nature Communications, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=920328 (Accessed April 26, 2024)