Quantum Science and Engineering at Cornell
Cornell’s Ithaca campus is home to a broad range of investigations into the quantum-mechanical nature of our world and universe, as well as the study of how to harness effects that are uniquely quantum mechanical for producing new technology in computing, communication, and sensing.
This website serves as a central source of information about who is working on quantum science and engineering at Cornell, what research areas we cover, and what quantum-related events are taking place.
Upcoming Events
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News and Breakthroughs
Soundwaves settle debate about elusive quantum particle
In 2018, researchers in Japan claimed to find concrete evidence of an elusive particle, a Majorana fermion, in a quantum spin liquid called ruthenium trichloride. Majoranas are highly sought-after by quantum materials scientists because when a pair are localized, or trapped, they can securely encode information and form a stable qubit – the building block of quantum computing.
Some researchers heralded the finding and used it to launch their own studies, while others believed the breakthrough – which was made by measuring what’s called the thermal Hall effect – was actually a mirage caused by defects in the material sample.
Cornell researchers have now waded into the debate and their findings, published April 22 in Nature, show both camps were wrong. By measuring the movement of soundwaves rather than the flow of heat, the team discovered the thermal Hall effect was caused by rotating lattice vibrations called chiral phonons.
First quantum oscillations observed in gallium nitride holes
Gallium nitride, a semiconductor that can operate at high voltages, temperatures and frequencies, has enabled technologies from LED lighting to high-power electronics. Now Cornell researchers have observed a quantum property of the material for the first time, an advance that could expand its technological reach.
Much of gallium nitride’s value as a semiconductor lies in how quickly negatively charged electrons move through the material. But the material could become even more useful if scientists better understood its positively charged “holes,” which behave like mobile pockets of missing electrons but have been difficult to study. Understanding how to control the flow of the holes – as engineers have achieved in silicon semiconductors – would allow gallium nitride to reach its full potential.
In a new study published March 23 in Nature Electronics, researchers report the first observation of quantum oscillations of holes confined in a sheet – called two-dimensional hole gas – at the interface of gallium nitride and aluminum nitride.
Holding chaos at bay in the quantum world
Preserving quantum information is key to developing useful quantum computing systems. But interacting quantum systems are chaotic and follow laws of thermodynamics, eventually leading to information loss.
Physicists have long known of a strange exception, called dynamical freezing, when quantum systems shaken at precisely tuned frequencies evade these laws. But how long can this phenomenon postpone thermodynamics?
Not forever, but for an astonishingly long time, Cornell physicists have determined, giving the first quantitative answer. Using a new mathematical framework, they demonstrate that the frozen state can be stabilized long enough to be a useful strategy for preserving information in quantum systems.
If you’re working on quantum research at Cornell and would like to contribute material to this website, please email quantum@cornell.edu.