Quantum fluids and solids articles from across Nature Portfolio

Low-energy excitations of strongly correlated systems are described by the Tomonaga–Luttinger liquid theory. Here the authors employ Bragg spectroscopy to demonstrate a spin-incoherent Luttinger liquid in ⁶Li atoms using charge and spin excitations.

Quantum vortices exist in superfluid and play important role in superfluid characteristics. Here the authors determine quantum dissipation caused by mutual friction in superfluid by filming the motion of quantized vortex rings in superfluid helium.

Some materials can display magnetic order despite having spin-singlet ground state on individual magnetic sites. This arises due to exchange interactions mixing excited crystal electric field states. Here, Gao et al study and example of such a system, Ni₂Mo₃O₈, and find that crystal electric field states in both the paramagnetic and antiferromagnetic states exhibit dispersive excitations.

The Mott insulator κ-(BEDT-TTF)₂Cu₂(CN)₃ has been a strong candidate for a gapless quantum spin liquid, but recent experiments suggested a spin-gapped phase below 6 K. Pustogow et al. study the entropy of this phase by driving the system through the metal-insulator transition with a strain engineering approach.

It is very challenging to model hydrogen at high pressures and low temperatures because quantum effects become significant. A state-of-the-art numerical study shows that these effects cause important changes to the predicted phase diagram.

Quantum turbulence typically entails reconnecting quantized vortices as seen in quantum fluids. Experiments with superfluid helium now show turbulent dynamics with negligible vortex reconnection, a regime dominated by interacting vortex waves at all length scales.