Dynamically disordered magnetic states at sub-K regime in systems with strong magnetic interactions

Despite high-temperature magnetic susceptibility of Y₂CuTiO₆ exhibiting a large Curie Weiss scale of ~134 K, AC magnetic susceptibility, µSR, and specific heat data show that magnetic ordering and spin freezing are absent down to 50 mK. Heat capacity and magnetization as a function of the applied magnetic field and the temperature exhibit scaling collapses that are reminiscent of the random singlet physics. The suppression of any ordering or freezing scale, if at all present, by more than three orders of magnitude compared to the Curie-Weiss scale, in conjunction with the scaling behaviors, indicates exciting possibilities such as disorder-stabilized long range quantum entangled ground states. Prompted by this, we have explored low temperature thermodynamic and dynamic experimental signatures of several other related systems but with large spins (S > 1/2) and interestingly found similar hugely frustrated magnetic states without ordering or freezing down to the sub-K temperature regime.

 

Work done in collaboration with M. Baenitz, P. J. Baker, S. Bhattacharjee, S. Chattopadhyay, K. Damle, D. Das, R. Das, H. Fabian, T. Herrmannsdoerfer, A. Hossain, L. Hubertus, D. C. Joshi, P. Keerthi S, S. Kundu, P. Mahadevan, A. V. Mahajan, R. Mathieu, J.-C. Orain, S. Pujari, and K. M. Ranjith.