The very first appearance of a previously undetectable quantum excitation known as the axial Higgs mode — exciting in its own right — also holds great promise for developing and manipulating quantum materials at higher temperatures for quantum computers and quantum information science in general.
“In contrast to the regular Higgs mode, which is produced by a Higgs mechanism that provides mass to fundamental particles in the Standard Model of Particle Physics, the axial Higgs mode is visible at room temperature. This property enables more efficient and cost-effective experiments for manipulating quantum materials for a variety of applications — including next-generation memory storage and optoelectronic devices — that would otherwise require extremely low temperatures,” according to an article written by Elizabeth Rosenthal and Posted today on the Quantum Science Center website.
The axial Higgs mode manifests as a low-energy excitation in rare-earth tellurides, a class of quantum materials notable for exhibiting charge density wave or CDW interactions. This behavior refers to arrangements of interacting electrons in quantum materials that form specific patterns and correlations.
The team responsible for these results, which are: published in Nature, was led by researchers from Boston College and includes scientists from Harvard University, Princeton University, University of Massachusetts Amherst, Yale University, University of Washington, and the Chinese Academy of Sciences.
“This result is almost elegant in its simplicity — it’s really rare to find a new particle with a super-pure signature without much ado,” said Prineha Narang, quoted in the article. Narang is an assistant professor at Harvard and principal investigator at the QSC, a US Department of Energy National Quantum Information Science Research Center headquartered at DOE’s Oak Ridge National Laboratory.
To measure the axial Higgs mode, the researchers used Raman spectroscopy — a nearly 100-year-old technique designed to characterize the structure and properties of complex materials — to observe path interference, demonstrating the power of quantum mechanics to to control matter. They found this interference of quantum pathways in multiple rare-earth CDW systems, and this phenomenon persisted up to room temperature and was insensitive to the mixing of the axial Higgs mode with nearby phonons or vibrations in the material.
The most notable quantum activity occurs only at very low temperatures, requiring dilution refrigerators that rely on a limited supply of liquid helium. Otherwise, the physics of quantum materials is usually completely invisible or obscured by noise, allowing certain properties to disappear in and out of sight so quickly that they cannot be confirmed or properly studied. Although the team cooled their CDW samples, they found that the signature, or wavelength produced by spectroscopy measurements, remained just as clean when the materials were warmed to room temperature.
The researchers expect that the axial Higgs mode probably also exists elsewhere, including in superconductors and magnetic materials, which allow experimenters to study and optimize quantum systems without depending on extreme conditions or large-scale facilities.
Link to the full article, https://qscience.org/evasive-quantum-phenomenon-makes-debut-in-routine-tabletop-experiment/