Magnetic field induced orbital polarization in cubic YbInNi4: determining the quartet ground state using x-ray linear dichroism

• Published in: Physical review letters Vol. 107; no. 23; p. 236402
• Main Authors: Willers, T, Cezar, J C, Brookes, N B, Hu, Z, Strigari, F, Körner, P, Hollmann, N, Schmitz, D, Bianchi, A, Fisk, Z, Tanaka, A, Tjeng, L H, Severing, A
• Format: Journal Article
• Language: English
• Published: United States 02.12.2011
• ISSN: 1079-7114
• DOI: 10.1103/PhysRevLett.107.236402

We have been able to induce a linear dichroic signal in the Yb M(5) x-ray absorption white line of cubic YbInNi(4) by the application of a magnetic field. The nonzero integrated intensity of the magnetic field induced dichroic spectrum indicates a net noncubic 4f orbital polarization. A quantitative analysis of the temperature and field strength dependence establishes that the crystal-field ground state is a Γ(8) quartet. The results demonstrate the potential of magnetic field induced linear dichroism as a new powerful approach for the investigation of the degeneracy and orbital degrees of freedom of cubic heavy-fermion and Kondo systems.