Brightened Optical Transition Hinting to Strong Spin-Lattice Coupling in a Layered Antiferromagnet.

Two-dimensional (2D) van der Waals magnets show strong interconnection between their electrical, magnetic, and structural properties. Here, the emergence of a luminescent transition is revealed upon crossing the Néel transition temperature of CrPS, a layered antiferromagnetic semiconductor. This luminescent transition occurs above the lowest absorption level.

Thermal and electrostatic tuning of surface phonon-polaritons in LaAlO/SrTiO heterostructures.

Phonon polaritons are promising for infrared applications due to a strong light-matter coupling and subwavelength energy confinement they offer. Yet, the spectral narrowness of the phonon bands and difficulty to tune the phonon polariton properties hinder further progress in this field. SrTiO - a prototype perovskite oxide - has recently attracted attention due to two prominent far-infrared phonon polaritons bands, albeit without any tuning reported so far.

Reconciling scaling of the optical conductivity of cuprate superconductors with Planckian resistivity and specific heat.

Materials tuned to a quantum critical point display universal scaling properties as a function of temperature T and frequency ω. A long-standing puzzle regarding cuprate superconductors has been the observed power-law dependence of optical conductivity with an exponent smaller than one, in contrast to T-linear dependence of the resistivity and ω-linear dependence of the optical scattering rate. Here, we present and analyze resistivity and optical conductivity of LaSrCuO with x = 0.

Propagation of shear stress in strongly interacting metallic Fermi liquids enhances transmission of terahertz radiation.

A highlight of Fermi-liquid phenomenology, as explored in neutral [Formula: see text]He, is the observation that in the collisionless regime shear stress propagates as if one is dealing with the transverse phonon of a solid. The existence of this "transverse zero sound" requires that the quasiparticle mass enhancement exceeds a critical value. Could such a propagating shear stress also exist in strongly correlated electron systems? Despite some noticeable differences with the neutral case in the Galilean continuum, we arrive at the verdict that transverse zero sound should be generic for mass enhancement higher than 3.