Unexpected new states of matter that challenge existing theories have been revealed in recent investigations by researchers at Georgia State University, whose studies of fractional quantum Hall effects (FQHE) could signal new advancements in quantum computing and materials science.
The discoveries were made during research led by Professor Ramesh G. Mani and recent Ph.D. graduate U. Kushan Wijewardena, whose studies of FQHE have revealed new non-equilibrium states of matter that could have profound implications for future technologies.
Mani and Wijewardena’s findings, published in Communications Physics, now point to the existence of new, non-equilibrium states of matter resulting from their studies of FQHE.
The Perplexing World of Fractional Quantum Hall Effects
FQHE is a phenomenon where electrons behave in unexpected ways under extreme conditions presented within a special two-dimensional space. The phenomenon is caused by the grouping of electrons, which interact with magnetic fields to form what physicists call quasiparticles, which possess only a fraction of an electron’s charge.
FQHE has long been a subject of intrigue for physicists since it reveals unique properties of properties within two-dimensional systems, which are conceptually similar to ideas explored in Edwin Abbot’s classic 1884 novella Flatland.
Specifically, FQHE is relevant to condensed matter physics, resulting in Nobel Prizes that included recognition for the discovery of the quantum Hall effect and the fractional quantum Hall effect. Such discoveries would pave the way for the development of a range of modern technologies, including smartphones and advancements in quantum computing that are currently underway.
Unexpected Splitting of FQHE States
In their recent experiments, Mani and Wijewardena studied the phenomenon’s effects within a magnetic field roughly 100,000 times greater than Earth’s at very low temperatures. Applying a supplementary current to high-mobility semiconductor devices composed of layered structures possessing gallium arsenide (GaAs) and aluminum gallium arsenide (AlGaAs), the researchers were able to explore some of the more unique aspects of FQHE in ways never before achieved.
Among their findings, the team reports the observation of unexpected splitting of FQHE states and crossings of their respective split branches. This innocuous-sounding discovery has major potential significance since it revealed what appear to be new states of matter that have never been observed previously.
In a statement, Mani compared their observations to exploring the upper floors of a building. Many people purchase or rent homes and seldom, if ever, ascend into the attic or crawlspace, which remain largely unexplored. However, unlike the unexplored reaches of most homes, the unexplored “floors” of the team’s FQHE explorations revealed complex signatures of excited states in the quantum system, discoveries that could have significant implications.
Observations Reveal New States of Matter
“We have been working on these phenomena for many years, but this is the first time we’ve reported these experimental findings on achieving excited states of fractional quantum Hall states induced by applying a direct current bias,” Wijewardena said in a recent statement.
“The results are fascinating, and it took quite a while for us to have a feasible explanation for our observations.”
According to Wijewardena, the team’s results could even suggest a hybrid origin for the observed non-equilibrium excited-state FQHEs.
The new research, while potentially challenging existing theories related to FQHEs, could also open new avenues for research in the field of condensed matter physics. In the years ahead, such studies could extend well beyond the laboratory to offer potential quantum computing and materials science breakthroughs, which could lead to revolutionary future technologies.
Going forward, Wijewardena and Mani plan to extend their explorations into such extreme conditions and see whether additional observations of FQHE under such conditions reveal its deeper nuances, thereby revealing more potentially crucial insights that could propel future technologies.
Wijewardena, Mani, and their team’s recent study, “Non-equilibrium excited-state fractionally quantized Hall effects observed via current bias spectroscopy,” appeared in Communications Physics on August 6, 2024.
Micah Hanks is the Editor-in-Chief and Co-Founder of The Debrief. He can be reached by email at micah@thedebrief.org. Follow his work at micahhanks.com and on X: @MicahHanks.