Eur. Phys. J. B (2012) 85: 278
https://doi.org/10.1140/epjb/e2012-30359-8

Regular Article

Magnetocaloric effect in spin-1/2 XX chains with three-spin interactions

¹ Institute for Condensed Matter Physics, National Academy of Sciences of Ukraine, 1 Svientsitskii Street, 79011 L’viv-11, Ukraine
² Department for Theoretical Physics, Ivan Franko National University of L’viv, 12 Drahomanov Street, 79005 L’viv-5, Ukraine
³ Department of Theoretical Physics, Yerevan State University, Al. Manoogian 1, 0025 Yerevan, Armenia

^a e-mail: derzhko@icmp.lviv.ua

Received: 3 May 2012
Received in final form: 21 June 2012
Published online: 8 August 2012

Abstract

We consider the exactly solvable spin-1/2 XX chain with the three-spin interactions of the XZX + YZY and XZY − YZX types in an external (transverse) magnetic field. We calculate the entropy and examine the magnetocaloric effect for the quantum spin system. We discuss a relation between the cooling/heating efficiency and the ground-state phase diagram of the quantum spin model. We also compare ability to cool/heat in the vicinity of the quantum critical and triple points. Moreover, we examine the magnetocaloric effect for the spin-1/2 XX chain with three-spin interactions in a random (Lorentzian) transverse magnetic field.