Electrons – the carriers of electricity – are inherently quantum mechanical, exhibiting remarkable behaviors like tunneling through barriers, occupying multiple locations at the same time, and even becoming entangled over distances.
“Yet for decades, these extraordinary properties remained hidden in everyday materials,” said physicist Shahal Ilani.
In the spring 2025 Bethe Lecture, “Quantum Mechanics with a Twist,” Ilani, professor at the Weizmann Institute of Science, will introduce the emerging field of twistronics, which is revolutionizing our ability to harness quantum phenomena. The public lecture is Wednesday, April 9 at 7:30 p.m. in Schwartz Auditorium, Rockefeller Hall 201.
“By peeling materials into atomically thin layers and reassembling them with a deliberate twist, researchers have discovered that we can craft artificial materials where electrons behave in astonishing, unconventional ways,” Ilani said. “Twistronics is reshaping our understanding of quantum behavior and opening doors to entirely new realms of quantum materials.”
When these atomically thin layers are aligned at a precise angle relative to each other, beautiful phenomena arise, but the earliest exciting results were based on layers stacked with relatively crude control, making each sample its own unique system, said Katja Nowack, associate professor of physics in the College of Arts and Sciences (A&S).
“Shahal has invented an entirely new way to control the alignment of the layers precisely and in-situ,” Nowack said. “Thus far, we’ve only caught first glimpses of this new technique, dubbed ‘the quantum twisting microscope.’ I can’t wait to see what else this microscope will reveal. Shahal is known for some of the most elegant experiments in condensed matter physics I’ve encountered. I anticipate this will be a truly inspiring talk for anyone who wants to be awed by the beauty of quantum mechanics and materials.”
Ilani’s research pushes the boundaries of condensed matter physics, combining the invention of innovative experimental tools with groundbreaking fundamental physics discoveries, said Nowack. His group at the Weizmann Institute pioneered the world’s most sensitive scanning microscope for imaging electric charge, capable of detecting one-millionth of a single electron charge with nanoscale resolution. Using this microscope, they have achieved several landmark discoveries.
Ilani's latest invention is the Quantum Twisting Microscope (QTM), a transformative tool that allows forming a twistable interface between atomically thin layered materials. By leveraging quantum interference at its tip, this microscope probes the electronic waves within quantum materials in the most direct way, detects collective modes, and images electronic potentials at unprecedented scales.
Among other awards, Ilani has received the Helen and Martin Kimmel Award for Innovative Investigation, the Rosa and Emilio Segre Research Award, three ERC awards from the European Union, and the Wolf Foundation Krill Prize for Excellence in Scientific Research.
Ilani is no stranger to Ithaca, Nowack said. He was a postdoctoral researcher at Cornell from 2004 to 2008.
In addition to the public Bethe Lecture, Ilani will give a physics colloquium talk, “The Quantum Twisting Microscope: Visualizing Waves in Quantum Matter,” on Monday, April 7 at 4 p.m. in Schwartz Auditorium, Rockefeller Hall 201.
He will also participate in a Laboratory of Atomic and Solid State Physics (LASSP) special seminar, “What is the ultimate conductance of hydrodynamic electrons,” on Tuesday, April 8, at 2:30 p.m. in 700 Clark Hall.
The Hans Bethe Lecture Series, established by the Department of Physics and the College of Arts and Sciences, honors Bethe, Cornell professor of physics from 1936 until his death in 2005. Bethe won the 1967 Nobel Prize in physics for his description of the nuclear processes that power the sun.
