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Orion Gerguri

Publications and source records attributed to Orion Gerguri.

2 recordsLinked to original sources

Lifting the degeneracy of quantum spin liquid phase by uniaxial pressure

We report muon spin relaxation/rotation ($\mu$SR) measurements of the candidate three-dimensional (3D) quantum spin liquid (QSL) PbCuTe$_2$O$_6$, hosting $S=1/2$ moments, under controlled in situ [110] uniaxial compression up to $\sigma_{[110]}=37.7$~MPa. A small directional lattice perturbation significantly modifies the local magnetic response, while above $\sigma_{\rm cr}\sim10.8$\,MPa the relaxation rates are strongly enhanced and the internal-field distribution is substantially broadened. These changes occur along with the local crystalline symmetry breaking. While, no evidence for conventional static long-range magnetic order is observed, the compression drives the system towards a structurally modified and strongly correlated state in which enhanced quasi-static correlations coexist with persistent slow spin dynamics. This work demonstrates a clean and symmetry-selective route to control frustrated exchange landscape and access hidden magnetic instabilities in a 3D QSL candidate opening up the possibilities to tune other correlated systems where intrinsic coupling between magnetic and lattice degrees of freedom are relevant.

cond-mat.str-el

Direct High-Magnetic-Field Coupling to Stripe Order in a Cuprate Superconductor

Superconductivity in cuprates emerges out of a complex normal state that hosts density waves, pseudogap physics, and strange metal properties. Here, we access this normal state by synchronizing free-electron laser x-rays with high-magnetic-field pulses up to 44 T. We observe a linear increase in charge order amplitude and correlation length that persists far above the vortex melting transition. This behavior is incompatible with standard phase competition between charge order and superconductivity. By means of conventional hard x-ray diffraction and magnetostriction, we show that applied fields also enhance monoclinic lattice distortions. However, this magnetoelastic response is weaker and an epiphenomenon of the stripe order enhancement. Combined with recent observations of field-linear spin freezing, our results point to a direct coupling between magnetic field and the spin component of stripe order in the high-field normal state -- a mechanism independent of superconductivity suppression that has so far remained hidden from scattering probes.

cond-mat.str-el