Related Experiment Video
Updated: Aug 12, 2026
10:42
Combining Solid-state and Solution-based Techniques: Synthesis and Reactivity of Chalcogenidoplumbates(II or IV)
Published on: December 29, 2016
Ring exchanges and the supersolid phase of 4He
1Department of Physics and NCSA, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA. ceperley@uiuc.edu
Physical Review Letters
|November 5, 2004
Summary
Ring exchange in helium-4 (4He) crystals does not support supersolid behavior. Simulations show that even with many exchanging atoms, superfluidity is unlikely in perfect 4He crystals.
Area of Science:
- Condensed Matter Physics
- Quantum Materials
Background:
- Supersolids, materials exhibiting both solid and superfluid properties, are of significant interest.
- Helium-4 (4He) is a prime candidate for supersolid behavior due to quantum effects like zero-point motion.
Purpose of the Study:
- To investigate the potential for supersolid behavior in hexagonal close-packed (hcp) 4He.
- To determine if atomic ring exchange frequencies support nonclassical rotational inertia.
Main Methods:
- Utilized path integral Monte Carlo simulations to model atomic exchanges.
- Calculated exchange frequencies in bulk hcp 4He.
- Fitted frequencies to a lattice model.
Main Results:
- Exchange frequencies were calculated for atoms undergoing ring exchange.
- Analysis indicated that the scaling with the number of exchanging atoms does not favor superfluidity.
- The conditions for nonclassical rotational inertia were not met.
Conclusions:
- Superfluid behavior is unlikely to be observed in a perfect 4He crystal.
- Atomic ring exchange dynamics in hcp 4He do not appear sufficient to form a supersolid state.
More Related Videos
08:55Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses
Published on: June 7, 2018
10:52Line Shape Analysis of Dynamic NMR Spectra for Characterizing Coordination Sphere Rearrangements at a Chiral Rhenium Polyhydride Complex
Published on: July 27, 2022
Related Concept Videos
02:31Phase Transitions
Whether solid, liquid, or gas, a substance's state depends on the order and arrangement of its particles (atoms, molecules, or ions). Particles in the solid pack closely together, generally in a pattern. The particles vibrate about their fixed positions but do not move or squeeze past their neighbors. In liquids, although the particles are closely spaced, they are randomly arranged. The position of the particles are not fixed—that is, they are free to move past their neighbors to occupy...
02:39Phase Transitions: Melting and Freezing
Heating a crystalline solid increases the average energy of its atoms, molecules, or ions, and the solid gets hotter. At some point, the added energy becomes large enough to partially overcome the forces holding the molecules or ions of the solid in their fixed positions, and the solid begins the process of transitioning to the liquid state or melting. At this point, the temperature of the solid stops rising, despite the continual input of heat, and it remains constant until all of the solid is...
02:33Phase Transitions: Sublimation and Deposition
Some solids can transition directly into the gaseous state, bypassing the liquid state, via a process known as sublimation. At room temperature and standard pressure, a piece of dry ice (solid CO2) sublimes, appearing to gradually disappear without ever forming any liquid. Snow and ice sublimate at temperatures below the melting point of water, a slow process that may be accelerated by winds and the reduced atmospheric pressures at high altitudes. When solid iodine is warmed, the solid sublimes...
01:19Phase Diagram
The phase of a given substance depends on the pressure and temperature. Thus, plots of pressure versus temperature showing the phase in each region provide considerable insights into the thermal properties of substances. Such plots are known as phase diagrams. For instance, in the phase diagram for water (Figure 1), the solid curve boundaries between the phases indicate phase transitions (i.e., temperatures and pressures at which the phases coexist).
01:21Phase Transitions
A phase transition is the process in which a substance changes from one state of matter to another, like from a solid to a liquid, liquid to gas, or vice versa, at a specific temperature and under given pressure conditions. This change is spontaneous and is affected by alterations in temperature and pressure. These parameters impact the strength of the forces between molecules (intermolecular forces) in the substance.During a phase transition, both the initial and final phases of the substance...
01:24Solid–Solid Solutions
The temperature-composition phase diagram of two solids, A and B, which are immiscible in the solid phase but form miscible liquids, shows that when the temperature is low, these two exist as separate, pure solids (A and B). As the temperature increases, they transition into a single-phase liquid solution where A and B coexist. Moving from point a1 to a2 in the phase diagram, the composition changes such that solid B begins to separate from the solution, enriching the remaining liquid with A.