Robert Hallock was awarded the 2025 Fritz London Memorial Prize, the most prestigious international prize in low-temperature physics. Bob is cited for “his many innovative achievements in the physics of liquid helium films and his pioneering work on supertransport in solid helium-4, which includes the paradigm-changing discovery of giant isochoric compressibility.”
Bob is one of just 58 recipients in the past 68 years. In that time, this field has seen intense scientific progress and growth into today's field of quantum matter physics. Here are excerpts from a scientific biography about Bob:
For many years his research efforts were centered on experimental studies of thin films of superfluid liquid helium including persistent or metastable film flow, the two-dimensional phase transition, the dynamical behavior of films on patterned substrates, 3He-4He mixture films, the wetting properties of helium to alkali-metal surfaces, studies of capillary condensation and avalanche phenomena of superfluid helium in porous materials and studies of the adsorption of He and H to carbon nanotube bundles. He has also studied the structure of helium by x-ray techniques, high transition temperature superconductors prepared by novel polymeric techniques, and macromolecular adsorption to surfaces at room temperature.
His most recent primary focus has been on solid helium, centered on the flow properties of helium through solid 4He held at fixed volume. [This was done using what has come to be known as the "UMass sandwich" design, built in the physics machine shop, and deployed in Bob's Hasbrouck basement lab] These studies determined that the flux was superfluid-like, that the temperature dependence of the flux was universal, that additions of 3He could cause the flow to cease at a low temperatures, and found the flow to have one-dimensional like behavior. And, importantly and quite unexpectedly, it was found that the density of the solid increased as flow through the solid took place.
For an account of the work that led to these discoveries on solid helium in please see an article by Bob in Physics Today . Please also see the story in UMass News. Some of this work was motivated by a close collaboration with Boris Svistunov and Nikolay Prokofiev and long-standing collaborations with Physics colleagues, students and postdocs.
Photo credit: Chris Amey