Density-wave order and pairing in pressurized CsCr3Sb5
In plain words
CsCr3Sb5, a chromium kagome metal, forms a density wave at normal pressure and becomes a superconductor near 6 K when squeezed, next to a metal whose resistance is linear in temperature; what the density wave is and whether its fluctuations pair the electrons is unknown.
Precise statement
At ambient pressure CsCr3Sb5 undergoes a coupled charge and spin density-wave transition at about 50 to 60 K; under pressure of roughly 40 kbar and above it is suppressed, superconductivity with $T_{c}$ up to $\sim 6\,\mathrm{K}$ appears, and the normal state shows non-Fermi-liquid resistivity (Liu et al., Nature 2024). Identify the density-wave order (wavevector, moment arrangement, altermagnetic or not) and determine whether its quantum critical fluctuations drive pairing. An answer is a refined magnetic structure and pressure phase diagram from neutron scattering, muSR or NMR under pressure, plus a gap-symmetry measurement in the superconducting phase.
What would settle it
Magnetic structure determination at ambient pressure followed under pressure to the superconducting dome, with gap structure from penetration depth or NMR under pressure.
Status in the literature
Unverified note
An altermagnetic ground state of the distorted structure was proposed in 2025 (Nature Communications); the order under pressure near the superconducting dome is unmeasured.