Princeton Physicists Find New Quantum Hall States
Researchers at Princeton University observed new even-denominator fractional quantum Hall states in a gallium arsenide quantum well.
Updated on Nov. 4, 2026 in Physics
Princeton University researchers observed new even-denominator fractional quantum Hall states in a 72.5-nanometre-wide gallium arsenide quantum well cooled to about 33 millikelvin. The states were identified at filling factors 3/4 and 5/4, alongside a previously reported state at 3/2.
Why it matters
The findings add to understanding of how electrons organize into exotic collective states when confined to thin layers at extremely low temperatures. The states depend on a nearly equal charge distribution between two layers, showing how electron interactions within and between layers stabilize them.
The measurements were taken in a 72.5-nanometre-wide gallium arsenide quantum well cooled to about 33 millikelvin, identifying filling factors 3/4 and 5/4 alongside a previously reported 3/2 state. Whether the 5/4 state exists in a second, more fragile form remains to be tested.
The players
Princeton University
Princeton University is a private research university in Princeton, New Jersey, known for its strong physics department and condensed matter research.
The details
By changing the electron density, the researchers controlled whether electrons behaved as one group or as two interacting layers. Shifting a small amount of charge between the layers caused the new states to weaken or disappear, confirming their dependence on a nearly equal charge distribution.
The Big Picture
The discovery extends decades of work on fractional quantum Hall physics in two-dimensional electron systems, a field in which Princeton's condensed matter group has been active. By identifying new even-denominator states in a double-layer configuration, the research moves beyond single-layer observations toward understanding how interlayer interactions create exotic electron phases.
Understanding how electrons organize into exotic states could eventually inform the design of future quantum materials and devices. The near-term impact is confined to laboratory research, as the states exist only at very low temperatures and require precise control.
The takeaway
Fundamental discoveries in quantum materials often take years to translate into practical technology, so the value here lies in deeper scientific understanding. Readers interested in the field can follow ongoing condensed matter research for further developments.
Further reading
Explore more on Physics to see how researchers are probing the behavior of electrons in extreme conditions.
