Seminar FO

Dear colleagues,

I would like to invite you to the seminar by Prof. Denis Arčon from the Institut "Jožef Stefan" and Faculty of mathematics and physics, University of Ljubljana, Slovenia

"Frustration in antiferromagnetic systems - laboratory for new states of matter"

Location: Department of Physics, F-08 (large lecture hall)

Time: 14:00 (sharp) on Tuesday, February 27th, 2018

----SEMINAR ABSTRACT--------------------------------------------------

The field of quantum magnetism has proven to be a very rich playground to uncover novel states of matter. Low dimensional antiferromagnets remain model systems to stabilize ground states where quantum fluctuations dominate the low-temperature physics. In conventional antiferromagnets, magnetic moments align antiparallel with respect to the nearest neighbour moments below a characteristic Neel temperature. However, in certain low dimensional magnetic systems with geometrically frustrated lattice not all interactions can be pairwise optimised. In such cases, the role of geometrical frustration is typically manifested in a drastic suppression of Neel temperature, in a state with a very complicated non-collinear magnetic order or even in a complete suppression of long range magnetic order and establishment of elusive quantum spin liquid. In this talk I will demonstrate the crucial role of geometrical frustration on selected

examples: the beta-TeVO4 compound comprising frustrated chains [1,2] and the layered 1T-TaS2 with a triangular lattice [3].

[1] M. Pregelj, A. Zorko, O. Zaharko, H. Nojiri, H. Berger, L.C. Chapon, D. Arčon, Nat. Comm. 6, 7255 (2015).

[2] M. Pregelj et al., Phys. Rev. B 94, 081114(R) (2016).

[3] M. Klanjšek, A. Zorko, R. Žitko, J. Mravlje, Z. Jagličić, P. K.

Biswas, P. Prelovšek, D. Mihailović, D. Arčon, Nat. Phys. 13, 1130 (2017).

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Srdačno,

Mihael Makek