Effect of impurities on spin-dimerization in a hybrid chain/ladder system

Datum

24.07.2017

Zeit

10:00 - 11:00

Sprecher

Bag Rabindranath

Zugehörigkeit

Indian Institute of Science Education and Research, Pune, India

Sprache

en

Hauptthema

Materialien

Andere Themen

Materialien, Physik

Host

Christine Malbrich

Beschreibung

Abstract Low-dimensional quantum magnets are presently an interesting field of study because of their unique and non-trivial properties. Sr14Cu24O41, a well-studied quasi-one-dimensional quantum magnet consisting of a hybrid chain/ladder structure. The ladders in this compound are known to exhibit a spin-singlet ground state, whereas the chains harbor spin-1/2 dimers that form an intervening Zhang-Rice singlet. The presence of some residual ‘free’ spins in the chain exhibit long-distance quantum entanglement at low temperatures [1]. We have grown high quality single crystals of Sr14Cu24O41 doped with dilute magnetic and nonmagnetic impurities, using the TSFZ method [2]. We investigate the effect of dilute doping (< 1 %) on the spin-dimerization in the chain sublattice using susceptibilities and specific heat. The dimerization gap remains isotropic and constant in magnitude upon doping with Zn, Ni and Al. However, with Co-doping, we witness an anisotropic closing of the dimerization gap; for H || chain, the gap supresses rapidly, whereas the gap remains almost unchanged for the perpendicular to chain. [1] S. Sahling et. al. Nature Physics 11, 255-260 (2015) [2] R, Bag et. al. Journal of Crystal Growth 458, 16-26 (2017)

Links

• Seminars at the IFW

Letztmalig verändert: 24.07.2017, 09:53:46