2015/10/23 by M. Jeong, Minki Jeong, H. M. Rønnow · 1 citation
Mathematics · Physics and Astronomy · #Algorithm #Mathematics #Physics #Physics of Superconductivity and Magnetism #Quantum and electron transport phenomena #Quantum many-body systems #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.92.180409
published as Phys. Rev. B 92, 180409(R) (2015) · 5 pages
arxiv created 2015/10/23 · openalex publication_date 2015/11/13 · arxiv updated 2015/11/16 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We demonstrate quantum critical scaling for an S=1/2 Heisenberg antiferromagnetic chain compound Cu(C4H4N2)(NO3)2 in a magnetic field around saturation, by analyzing previously reported magnetization [Y. Kono et al., Phys. Rev. Lett. 114, 037202 (2015)], thermal expansion [J. Rohrkamp et al., J. Phys.: Conf. Ser. 200, 012169 (2010)], and NMR relaxation data [H. K"uhne et al., Phys. Rev. B 80, 045110 (2009)]. The scaling of magnetization is demonstrated through collapsing the data for a range of both temperature and field onto a single curve without making any assumption for a theoretical form. The data collapse is subsequently shown to closely follow the theoretically predicted scaling function without any adjustable parameters. Experimental boundaries for the quantum critical region could be drawn from the variable range beyond which the scaled data deviate from the theoretical function. Similarly to the magnetization, quantum critical scaling of the thermal expansion is also demonstrated. Further, the spin dynamics probed via NMR relaxation rate 1/T1 close to the saturation is shown to follow the theoretically predicted quantum critical behavior as 1/T1\ensuremath∝T^\ensuremath-0.5 persisting up to temperatures as high as kBT\ensuremath≃J, where J is the exchange coupling constant.