Caltech physicists finally measure a quantum energy ladder predicted 40 years ago

Physicists often describe this universal behavior using a mathematical framework known as conformal field theory.

"The energy levels predicted by these theories are important because they encode profound information about the theories themselves," Alicea says.

For about 40 years, physicists have used conformal field theories to calculate how far apart those energy rungs should be.

Measuring a hidden energy ladder To detect the predicted energy levels, the researchers developed a technique called many body modulation spectroscopy.

"In two dimensions, the conformal field theories are not as well understood, so this is an exciting opportunity," Sun says.