Simulation: Quantum Leaps
Quantum simulation, broadly speaking, is an attempt to use orderly systems such as a grid of atoms to model much more complicated things — new particles, for example, or high-temperature superconductors. The behavior of such systems cannot be derived by hand, and even the world’s fastest supercomputers can’t model them.
Quantum simulators are the lesser sibling of an idea in physics known as quantum computers, which have been touted for more than three decades as a way to do everything from complex modelling to code-breaking. What the simulators and computers share is an ability to operate by the rules of quantum mechanics. Where they differ is in computational power: quantum computers are general-purpose machines able to carry out any possible algorithm, whereas quantum simulators have to be tailored specifically for the problem at hand. Current-generation simulators are also tough to control, and they may not be able to tackle every problem. Nevertheless, the simulators are much easier to build than quantum computers. And researchers say that the devices will soon be able to solve at least some quantum problems that can’t be tackled in any other way.