29-Si NMR and Hidden Order in URu2Si2

Abstract

We present new 29-Si NMR spectra in URu2Si2 for varying temperature T, and external field H. On lowering T, the systematics of the low-field lineshape and width reveal an extra component (lambda) to the linewidth below T_N ~ 17 K not observed previously. We find that lambda is magnetic-field independent and dominates the low-field lineshape for all orientations of H with respect to the tetragonal c axis. The behavior of lambda indicates a direct relationship between the 29-Si spin and the transition at T_N, but it is inconsistent with a coupling of the nuclei to static antiferromagnetic order/disorder of the U-spin magnetization. This leads us to conjecture that lambda is due to a coupling of 29-Si to the system's hidden-order parameter. A possible coupling mechanism involving charge degrees of freedom and indirect nuclear spin/spin interactions is proposed. We also propose further experiments to test for the existence of this coupling mechanism.

4 pages, 4 figures, submitted to PRL

Cited by in corpus (19)

• Colloquium: Hidden Order, Superconductivity, and Magnetism -- The Unsolved Case of URu2Si2
• Rotational Symmetry Breaking in the Hidden-Order Phase of URu2Si2
• Fermi liquid instabilities in the spin channel
• Hidden Orbital Order in $UR{u}_{2}S{i}_2$
• Helicity Order: Hidden Order Parameter in URu${}_2$Si${}_2$
• Group theory and octupolar order in URu2Si2
• High Field Studies of the Hidden Order Transition in URu${}_2$Si${}_2$
• Hidden Order Behaviour in URu2Si2 (A Critical Review of the Status of Hidden Order in 2014)
• Electronic structure theory of the hidden order material URu${}_2$Si${}_2$
• Hidden and antiferromagnetic order as a rank-5 superspin in URu2Si2
• Neutron scattering studies on URu2Si2
• Specific Heat of URu${}_2$Si${}_2$ in Fields to 42 T: Clues to the 'Hidden Order'
• Itinerancy and Hidden Order in $UR{u}_{2}S{i}_2$
• The Case for Phase Separation in $UR{u}_{2}S{i}_2$
• Resonant X-Ray Scattering from URu_{2}Si_{2}
• Theory Perspective: SCES '05 Vienna
• Metamagnetism, quantum criticality, hidden order and crystal electric fields in URu2Si2
• Thermodynamic evidence for broken fourfold rotational symmetry in the hidden-order phase of URu2Si2
• 29Si nuclear magnetic resonance study of URu2Si2 under pressure