|Address:||Niels Bohr Institute|
I am working on the theory of magnetic structures and excitations in condensed matter systems with localized moments, i.e. primarily systems containing ions from the series of the Lanthanides or the Actinides. I have written a monograph on the subject in collaboration with Allan Mackintosh:
published by Clarendon Press, Oxford, England in 1991.
Des McMorrow, Henrik Rønnow and I have edited the proceedings of Magnetism in Metals, a symposium in memory of Allan Mackintosh (1936-95), Copenhagen, August 26-29, 1996 and published by The Royal Danish Academy of Sciences and Letters in Matematisk-fysiske Meddelelser 45 (1997).
J. Larsen, T. K. Schäffer, U. B. Hansen, S. L. Holm, S. R. Ahl, R. Toft-Petersen, J. Taylor, G. Ehlers, J. Jensen, H. M. Rønnow, K. Lefmann, and N. B. Christensen, Spin Excitations and Quantum Criticality in the Quasi One-Dimensional Ising-Like Ferromagnet CoCl2·2D2O in a Transverse Field. Phys. Rev. B 96, 174424 (2017).
R. Toft-Petersen, E. Fogh, T. Kihara, J. Jensen, K. Fritsch, J. Lee, G. E. Granroth, M. B. Stone, D. Vaknin, H. Nojiri, and N. B. Christensen, Field-induced reentrant magnetoelectric phase in LiNiPO4, Phys. Rev. B 95, 064421 (2017).
P. Babkevich, N. Nikseresht, I. Kovacevic, J. O. Piatek, B. Dalla Piazza, C. Kraemer, K. W. Krämer, K. Prokeš, S. Ma'taš, J. Jensen, and H. M. Rønnow, Phase diagram of diluted Ising ferromagnet LiHoxY1-xF4, Phys. Rev. B 94, 174443 (2016).
P. Babkevich, A. Finco, M. Jeong, B. Dalla Piazza, I. Kovacevic, G. Klughertz, K. W. Krämer, C. Kraemer, D. T. Adroja, E. Goremychkin, T. Unruh, T. Strässle, J. Jensen, and H. M. Rønnow, Neutron spectroscopic study of crystal field excitations and the effect of the crystal field on dipolar magnetism in LiRF4, R = Gd, Ho, Er, Tm and Yb, Phys. Rev. B 92, 144422 (2015).
J. Jensen, D. L. Quintero-Castro, A. T. M. N. Islam, K. C. Rule, M. Månsson, and B. Lake, The lineshape of the singlet-triplet excitations in the dimer system Sr3Cr2O8 to first order in the high-density 1/z expansion, Phys. Rev. B 89, 134407 (2014).