Jens Jensen           

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:

Jens Jensen and Allan R. Mackintosh: Rare Earth Magnetism: Structures and Excitations

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).

Recent publications:

J. Jensen, J. Larsen, and U. B. Hansen, Comprehensive cluster-theory analysis of the magnetic structures and excitations in CoCl₂·2H₂O. Phys. Rev. B 97, 024423 (2018).

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 LiHo_xY_1-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).

Recent seminars:

Linear Response Theory and the Random Phase Approximation (International workshop on McPhase, Heinz Maier - Leibnitz Zentrum, Munich, 5.-7. November 2014).

Chiral spin-wave excitations of the spin-5/2 trimers in the langasite compound Ba₃NbFe₃Si₂O₁₄ (TEMM, Rutherford-Appleton Laboratory, Oxfordshire, June 2011).

Bose-Einstein condensation - in the spin-dimer system TlCuCl₃(?) (Niels Bohr Institute, Copenhagen, November 2009).