Quantum physics

MIT researchers have observed “Hofstadter’s butterfly” – the quantum theory that proposes “under the right conditions, tiny electrons in a quantum system could produce an energy spectrum composed of fractals” that would resemble a butterfly, reports Gayoung Lee for Scientific American. The discovery, “emerged from the complex quantum dance of electrons sandwiched between two microscopic layers of graphene,” explains Lee. The results “were unexpected [as] the researchers involved weren’t even trying to hatch Hofstadter’s butterfly from its quantum chrysalis.” 

MIT physicists have measured kinetic inductance for two layers of stacked and twisted graphene and found that the superconducting current is much “stiffer,” meaning it resists change more than predicted by any conventional theory of superconductivity, reports Karmela Padavic-Callaghan for New Scientist. The findings could do more than “shed light on why graphene superconducts – they could also reveal key properties required for room-temperature superconductors.”

Postdoctoral research Wenxuan Jia PhD '24 and colleagues at the Laser Interferometer Gravitational-Wave Observatory (LIGO) have developed a way to reduce the impact of quantum noise by squeezing the laser light used in the detectors, enabling scientists to double the number of gravitational waves they can find, reports Karmela Padavic-Callaghan for New Scientist. “We realized that quantum noise will be limiting us a long time ago,” says Jia. “It’s not just a fancy [quantum] thing to demonstrate, it’s something that really affects the actual detector.” 

Postdoctoral associate Adam Forrest Kay’s book “Escape From Shadow Physics: The Quest to End the Dark Ages of Quantum Theory,” is reviewed by Andrew Crumey for The Wall Street Journal. “Consistently interesting” and “energetically written,” the book, “eloquently explains the history behind hydrodynamic quantum analogs,” writes Crumey.  

Prof. Seth Lloyd and other physicists have begun to show that in the quantum realm, theoretical routes to the past called time loops might be closer to reality, writes New Scientist’s Miriam Frankel. When first publishing his ideas about quantum time loops, Lloyd says he “probably wouldn’t have done it” given all the questions received about time travel, but now testing time loops is experimentally feasible.

Science reporter Jennifer Sills asked scientists to answer the question: “Imagine that you meet all of your research goals. Describe the impact of your research from the perspective of a person, animal, plant, place, object, or entity that has benefited from your success.” Xiangkun (Elvis) Cao, a Schmidt Science Fellow in the MIT Department of Chemical Engineering, shares his response from a photon’s perspective. “I am a photon,” writes Cao. “I started my journey entangled with my significant other at the beginning of the Universe. In the past, humans couldn’t understand me, but then physicists created a quantum computer. At last, I have been reunited with my life partner!”

Writing for Scientific American, Prof. Carlo Ratti explores the “transformative” potential of quantum sensors. Ratti writes that quantum sensors could enable autonomous vehicles to “‘see’ around corners, underwater navigation systems, early-warning systems for volcanic activity and earthquakes, and portable scanners that monitor a person's brain activity during daily life.”

Prof. Alan Guth speaks with Christina Couch of Science Friday about his career and the cosmos. Of what inspired him to pursue a career in science, Guth recalls conducting experiments with a friend and being “very excited about the idea that we can really calculate things, and they actually do reflect the way the real world works.”

Dan Vergano of National Geographic profiles Professor Alan Guth’s career in physics. "What always fascinated me about science was the desire to understand what underlies it all, and I think physics is basically the study of that," Guth explains.