Spatially Modulated Superfluid State in Two-Dimensional ${}^4$He Films

Abstract

The second layer of ${}^4$He films adsorbed on a graphite substrate is an excellent experimental platform to study the interplay between superfluid and structural orders. Here, we report a rigid two-frequency torsional oscillator study on the second layer as a function of temperature and ${}^4$He atomic density. We find that the superfluid density is independent of frequency, which can be interpreted as unequivocal evidence of genuine superfluidity. The phase diagram established in this work reveals that a superfluid phase coexists with hexatic density-wave correlation and a registered solid phase. This suggests the second layer as a candidate for hosting two exotic quantum ground states: the spatially modulated superfluid and supersolid phases, resulting from the interplay between superfluid and structural orders.

arXiv commentaccepted in Phys. Rev. Lett. (7 pages, 4 figure, Supplemental Materials)

References in corpus (35)

• Direct observation of competition between superconductivity and charge density wave order in YBa2Cu3Oy
• Theory of Intertwined Orders in High Temperature Superconductors
• Characterization of collective ground states in single-layer NbSe2
• Observation of the supersolid stripe phase in spin-orbit coupled Bose-Einstein condensates
• Supersolid formation in a quantum gas breaking continuous translational symmetry
• Fulde-Ferrell-Larkin-Ovchinnikov State in Heavy Fermion Superconductors
• The Physics of Pair Density Waves
• Supersolid hardcore bosons on the triangular lattice
• Low Temperature Shear Modulus Changes in Solid 4-He and Connection to Supersolidity
• Excitation spectrum of a trapped dipolar supersolid and its experimental evidence
• Intertwined vestigial order in quantum materials: nematicity and beyond
• Monitoring and manipulating Higgs and Goldstone modes in a supersolid quantum gas
• Concepts relating magnetic interactions, intertwined electronic orders and strongly correlated superconductivity
• Supersolid phase of hardcore bosons on triangular lattice
• Superglass Phase of Helium-four
• On the Supersolid State of Matter
• Probing the roton excitation spectrum of a stable dipolar Bose gas
• Visualizing the Energy-gap Modulations of the Cuprate Pair Density Wave State
• Phase diagram of 4He adsorbed on graphite
• 4He on a single graphene sheet
• Switching of magnetic domains reveals evidence for spatially inhomogeneous superconductivity
• Evidence for a Spatially-Modulated Superfluid Phase of ${}^3$He under Confinement
• Intertwined Orders in Heavy-Fermion Superconductor CeCoIn${}_5$
• Stabilized Pair Density Wave via Nanoscale Confinement of Superfluid ${}^3$He
• Phase diagram of second layer of helium adsorbed on graphite
• Superconductivity, charge- or spin-density wave, and metal-nonmetal transition in BaTi${}_2$(Sb${}_{1-x}$Bi${}_x$)${}_2$O
• Possible quantum liquid crystal phases of helium monolayers
• Layering transitions in superfluid helium adsorbed on a carbon nanotube mechanical resonator
• Interpreting Torsional Oscillator Measurements: Effect of Shear Modulus and Supersolidity
• Superfluid and supersolid phases of 4He on the second layer of graphite
• Second layer crystalline phase of helium films on graphite
• Competing phases in the high field phase diagram of (TMTSF)${}_2$ClO${}_4$
• Frequency-dependent Study of Solid Helium-4 Contained in a Rigid Double-torus Torsional Oscillator
• Superfluid-like TO Responses in Rotating Solid Helium
• Intertwined Superfluid and Density Wave Order in a $p$-Orbital Bose Condensate

Cited by in corpus (20)

• Self-bound dipolar droplets and supersolids in molecular Bose-Einstein condensates
• Supersolidity in ultra-cold dipolar gases
• Sub-unity superfluid fraction of a supersolid from self-induced Josephson effect
• Analytical theory of enhanced Bose-Einstein condensation in thin films
• Strain-induced superfluid transition for atoms on graphene
• Superfluid transition of the second layer of He-4 on graphite: does substrate corrugation matter?
• Supersolidity in the second layer of $para$-H${}_2$ adsorbed on graphite
• Unveiling Supersolid Order via Vortex Trajectory Correlations
• A Simple Experimental Setup for Simultaneous Superfluid-response and Heat-capacity Measurements for Helium in Confined Geometries
• Single-fluid model for rotating annular supersolids and its experimental implications
• Phase diagram and crystal melting of helium-4 in two dimensions
• Phases of ${}^4$He and H${}_2$ adsorbed on a single carbon nanotube
• H2 superglass on an amorphous carbon substrate
• Efficient simulations of Hartree--Fock equations by an accelerated gradient descent method
• Effects of substrate corrugation during helium adsorption on graphene in the grand canonical ensemble
• He-4 monolayer on Graphene: a Quantum Monte Carlo study
• On the Novel Superfluidity in the Second Layer of ${}^4$He on Graphite
• Accurate Helium-Benzene Potential: from CCSD(T) to Gaussian Process Regression
• Designing edge currents using mesoscopic patterning in chiral d-wave superconductors
• Growth of uniform helium submonolayers adsorbed on single-surface graphite observed by surface X-ray diffraction