Magnetic Field Induced Berezinskii-Kosterlitz-Thouless Correlations in 3-Dimensional Manganites

Ashoka, A and Bhagyashree, KS and Bhat, SV (2020) Magnetic Field Induced Berezinskii-Kosterlitz-Thouless Correlations in 3-Dimensional Manganites. In: MRS Advances .

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Abstract

Ideal two-dimensional (2D) Heisenberg magnets lack long range magnetic order. However, the XY model with spins confined to a plane shows a topological phase transition at a finite temperature corresponding to binding and unbinding of vortices. Experimental evidence for such Berezinskii-Kosterlitz-Thouless (BKT) transitions has been difficult to obtain in condensed matter systems, where, even a weak interlayer coupling that is invariably present leads to long-range order, pre-empting the BKT transition. The BKT signatures are still discernible above the long-range ordering temperature, however, in the characteristic exponential temperature dependence of the coherence length of the fluctuations. In this work we report that an applied magnetic field can induce such BKT correlations not only in quasi 2-dimensional systems but also in nominally 3-dimensional manganites undergoing antiferromagnetic transitions. We arrive at this unexpected conclusion based on our studies of temperature dependence of electron paramagnetic resonance (EPR) linewidth "H(T) of Cr3+ doped bismuth strontium manganite Bi0.5Sr0.5Mn1-xCrxO3 (x= 0.04, 0.1) (BSMCO04 and BSMCO10). Copyright © Materials Research Society 2020.

Item Type:	Journal Article
Publication:	MRS Advances
Publisher:	Materials Research Society
Additional Information:	The copyright of this article belongs to Materials Research Society
Keywords:	Antiferromagnetism; Bismuth compounds; Chromium compounds; Electron spin resonance spectroscopy; Magnetic fields; Manganese compounds; Manganites; Paramagnetic resonance; Strontium compounds; Temperature distribution; Topology, Antiferromagnetic transition; Applied magnetic fields; Berezinskii-Kosterlitz-Thouless transition; Condensed matter system; Electron paramagnetic resonances (EPR); Experimental evidence; Long range magnetic order; Temperature dependence, Electron energy analyzers
Department/Centre:	Division of Physical & Mathematical Sciences > Physics
Date Deposited:	15 Mar 2021 07:34
Last Modified:	15 Mar 2021 07:34
URI:	http://eprints.iisc.ac.in/id/eprint/67486

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