Researchers in the Kim Group predict a way to achieve fractionalization without a magnetic field, a theory they detail in “Fractionalization in Fractional Correlated Insulating States at n ± 1/3 Filled Twisted Bilayer Graphene,” published in Physical Review Letters Sept. 8. Dan Mao, a Bethe/Wilkins/Kavli Institute at Cornell (KIC) postdoctoral fellow in the Laboratory of Atomic and Solid State Physics (LASSP), is lead author. Kim and doctoral student Kevin Zhang are co-authors.

A team of 11 scientists reported in March in the journal Nature that they had discovered a room-temperature superconductor. Eight of those scientists have now asked Nature to retract their paper. That pits them against the man who led the research: Ranga P. Dias, a professor of mechanical engineering and physics at the University of Rochester in New York. In the past few years, Dr. Dias has made several extraordinary scientific claims, but he has also been embroiled in a series of allegations of scientific misconduct.

Veit Elser of Cornell University has just described a new way to elucidate a problem that has baffled mathematicians for over a century: How densely can identical spheres be packed as the dimension of the spheres and of the space they occupy grow ever larger [1]? Schemes for densely packing spheres have been worked out in low dimensions and for two special cases: 8 and 24 dimensions. (A sphere in n-dimensional space is a set of points that are the same fixed distance away from a given center point.) Surprisingly, some schemes in high dimensions are little better than a random approach. What’s more, a century of research has failed to improve on the result from Hermann Minkowski, a German mathematician who came up with the concept of four-dimensional spacetime, that with each additional dimension, the highest fraction of space that can be occupied by spheres falls by a factor of 2. Intuitively, the rate of decrease should be slower.

“It’s something like a dance in space,” said Jeevak Parpia, professor of physics in the College of Arts and Sciences (A&S). “The effect of this pairing, called a ‘fluctuation,’ is to scatter other non-paired partners and disrupt the overall transport of momentum.”

The Biophysical Society is proud to announce its 2024 Society Fellows. This award honors the Society’s distinguished members who have demonstrated excellence in science and contributed to the expansion of the field of biophysics. The Fellows will be honored at the Biophysical Society’s 68th Annual Meeting, being held in Philadelphia, Pennsylvania from February 10-14, 2024. Michelle D. Wang, Cornell University, USA, for advancing our understanding of transcription, replication, and chromatin dynamics through the lens of DNA mechanics and topology. 

Robust navigation is both critical for survival and dauntingly complex: Think of the speed and agility of an airborne fly. A multidisciplinary team of researchers led by Itai Cohen, professor of physics in the College of Arts and Sciences, will use the fruit fly, Drosophila melanogaster, to study how the brain forms a coherent representation from multisensory information, corrects for errors from perturbations and generates robust behaviors.

“Measuring the position of a quantum particle changes its momentum and vice versa. Similarly, for qubits there are quantities which change one another when they are measured. We find that certain random sequences of these incompatible measurements lead to the formation of a quantum spin-glass,” said Erich Mueller, professor of physics in the College of Arts and Sciences (A&S). “One implication of our work is that some types of information are automatically protected in quantum algorithms which share the features of our model.”

Applications for the Kavli 2023 Theory Postdoctoral Fellowships are now open! The deadline is September 29th, 2023.

Applications for the Kavli 2023 Experimental Postdoctoral Fellowships are now open! The deadline is October 14th, 2023.

In numerous strange metals, the characteristic time between electron collisions, with each other and against anything that they encounter in their path, is set by the Planck’s constant and the temperature, said Debanjan Chowdhury, assistant professor of physics in the College of Arts and Sciences and a co-author of the paper. A vast majority of the known high-temperature superconductors, when heated above their superconducting temperature, exhibit this property. This is why it has been believed for a while that the clue to understanding the origin of high-temperature superconductivity lies in understanding the common thread across these materials that leads to this universal Planckian time scale.