A new simulator may be the breakthrough that allows scientists to probe strange quantum phenomena.
Among the most exciting and intriguing areas of investigation in modern physics are the exotic effects seen when quantum objects “hover” between two quantum states. Fields which exist in this “quantum critical” regime include high-temperature superconductors and some quantum computing research.
Exciting as quantum criticality is, its complexity is a major drawback. The mathematics is often too difficult to solve and conventional modern computers not powerful enough to simulate the systems, particularly those with more than just a couple of atoms.
Researchers at Stanford University and the US Department of Energy are attempting to build a quantum simulator to probe quantum criticality.
“We’re always making mathematical models that we hope will capture the essence of phenomena we’re interested in, but even if we believe they’re correct, they’re often not solvable in a reasonable amount of time,” says Stanford physics professor David Goldhaber-Gordon.
Goldhaber-Gordon likens a quantum simulator to a mechanical solar system model. The model-maker turns a crank which, through a series of interlocked gears, gives a representation of the motion of the planets and moons and can be used as a predictive tool.
Read more: Quantum entanglement breakthrough sees Danish physicists achieve world first
Only, Goldhaber-Gordon’s team is seeking to simulate the highly probabilistic and exotic effects of quantum critical points.
They begin by thinking of these systems as a lattice of atoms in a sea of electrons.
To be useful, a quantum simulator needs to have stand-ins for the atoms that are near-identical and interact with each other as well as the electron reservoir. The simulator also needs to be tunable so that its parameters can be altered to gain insight into the physical effects.
This is easier said than done with most quantum simulators.
The researchers hit the jackpot based on the work of French physicist Frédéric Pierre. They developed a quantum simulator built on so-called “metal islands” sitting in specially-designed pools of electrons known as two-dimensional electron gas.
“They’re very difficult to make,” according to graduate student Winston Pouse. But make them they did. The team was successful in creating a two-atom quantum criticality simulator.
“While we have not yet built an all-purpose programmable quantum computer with sufficient power to solve all of the open problems in physics, we can now build bespoke analogue devices with quantum components that can solve specific quantum physics problems,” says team member Dr Andrew Mitchell from University College Dublin.
Read more: Physicists fire a dangerously powerful laser down their corridor in the middle of the night
The team hopes to build more efficient devices by reducing the size of the metal islands. They also believe their work can be readily scaled up to simulate larger systems.
The research is published in Nature Physics.
Originally published by Cosmos as New quantum simulator might probe the exotic effects of quantum criticality between two states
Evrim Yazgin
Evrim Yazgin has a Bachelor of Science majoring in mathematical physics and a Master of Science in physics, both from the University of Melbourne.
Read science facts, not fiction...
There’s never been a more important time to explain the facts, cherish evidence-based knowledge and to showcase the latest scientific, technological and engineering breakthroughs. Cosmos is published by The Royal Institution of Australia, a charity dedicated to connecting people with the world of science. Financial contributions, however big or small, help us provide access to trusted science information at a time when the world needs it most. Please support us by making a donation or purchasing a subscription today.
