Abstract
The thermal conductivity of heavy-fermion superconductor was measured with a magnetic field rotating in the tetragonal plane. The thermal conductivity exhibits a step within the high-field low-temperature (HFLT) phase, which exists above 8 Tesla within the superconducting state, when field is rotated through the antinodal [100] direction of the superconducting -wave order parameter. This anomaly indicates the presence of a third order parameter within the HFLT phase, similar to that of pure . Therefore, the HFLT state with triply intertwined orders, i.e., superconducting -wave, magnetic spin-density wave (SDW), and a putative superconducting -wave pair-density wave (PDW), is robust against 5% Nd doping. The second magnetic phase within the superconducting state below 8 Tesla, a low-field SDW, displays a hysteresis in thermal conductivity as a function of field magnitude, which is also revealing the existence of a third order consistent with a -wave PDW. Given different origins and properties of the HFLT and low-field SDW states, the presence of three intertwined orders in both phases is remarkable and of far-reaching consequences.
- Received 15 December 2017
- Revised 5 April 2018
DOI:https://doi.org/10.1103/PhysRevB.97.245120
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