Anomalous Metamagnetism in the Low Carrier Density Kondo Lattice YbRh3Si7

K Binod ,Julia Y Chan,Xiaxin Ding,R Schönemann,Luis Balicas,T Chen,Andriy H Nevidomskyy,Katherine A Benavides,John Singleton,Macy Stavinoha,Haoran Man,Pengcheng Dai,Vaideesh Loganathan ,Chikara Saito ,Jonathan Gaudet ,Dmitry Sokolov ,J W Lynn ,Daniel Rhodes ,D T Adroja ,Steve Carr ,Huibo Cao ,H C Walker ,Q R Zhang ,A A Aczel ,C L Huang ,V S Zapf ,Iain W H Oswald ,Yu-Che Chiu ,Qing Huang ,Alannah Hallas ,Emilia Morosan

doi:10.1103/physrevx.8.041047

Abstract

We report complex metamagnetic transitions in single crystals of the new low carrier Kondo antiferromagnet YbRh3Si7. Electrical transport, magnetization, and specific heat measurements reveal antiferromagnetic order at T_N = 7.5 K. Neutron diffraction measurements show that the magnetic ground state of YbRh3Si7 is a collinear antiferromagnet where the moments are aligned in the ab plane. With such an ordered state, no metamagnetic transitions are expected when a magnetic field is applied along the c axis. It is therefore surprising that high field magnetization, torque, and resistivity measurements with H||c reveal two metamagnetic transitions at mu_0H_1 = 6.7 T and mu_0H_2 = 21 T. When the field is tilted away from the c axis, towards the ab plane, both metamagnetic transitions are shifted to higher fields. The first metamagnetic transition leads to an abrupt increase in the electrical resistivity, while the second transition is accompanied by a dramatic reduction in the electrical resistivity. Thus, the magnetic and electronic degrees of freedom in YbRh3Si7 are strongly coupled. We discuss the origin of the anomalous metamagnetism and conclude that it is related to competition between crystal electric field anisotropy and anisotropic exchange interactions.

Highlights

Materials containing partially filled f orbitals are of great interest to the strongly correlated electron system community because of their quantum complexity
It is worth highlighting that the structure determined by neutron diffraction differs from the one used in the density functional theory (DFT) calculations; while both structures have alternating AFM coupled planes, in DFT, the moments point along the c axis, whereas experimentally they are found to point along the a axis
With the magnetic ground state resolved from neutron diffraction measurements, a better characterization of the correlations in YbRh3Si7 is needed since the H 1⁄4 0 resistivity, shown in Fig. 1(a), hinted at possible strong correlations and Kondo screening below about 30 K

Summary

INTRODUCTION

Materials containing partially filled f orbitals are of great interest to the strongly correlated electron system community because of their quantum complexity. Among f-electron systems, the ground states of many Ce-, Yb-, and U-based compounds are highly susceptible to tuning by nonthermal control parameters, such as pressure, chemical substitution, or magnetic field [1] This often results in emergent phenomena, with unconventional superconductivity [2,3,4], non-Fermi liquid behavior near a quantum critical point [3,5,6,7,8,9], hidden order [4], and metamagnetism being just a few prominent examples [10,11,12,13,14,15,16,17,18]. Understanding the metamagnetism in YbRh3Si7 will help draw a more complete picture of how subtle quantum effects steer the macroscopic behavior of different materials

METHODS

LOW CARRIER ANTIFERROMAGNET WITH STRONG MAGNETIC ANISOTROPY

KONDO EFFECT AND HYBRIDIZATION

HARD-AXIS METAMAGNETISM

Findings

DISCUSSION