Quantum Mechanical (QM) simulation

  • Richard Feynman put it in memorable words: “Nature isn’t classical, dammit, and if you want to make a simulation of nature, you’d better make it quantum mechanical, and by golly it’s a wonderful problem, because it doesn’t look so easy.”
  • Simulating one quantum system using another, more controllable one has turned out to be not so easy, indeed. But much progress has been made since 1981, when Feynman delivered his seminal lecture ‘Simulating Physics with Computers’. The tremendous advances in isolating, manipulating and detecting single quantum systems — particularly in the past decade or so — mean that physical  implementations of ‘quantum simulators’ are now becoming a reality.


  • Quantum simulation has spiked a great deal of interest in the recent years. Firstly due to the broad spectrum of potential applications, ranging from physics, chemistry and even biology.

Schematic representation of a quantum system and a corresponding quantum simulator.

  • See bellow figure. Simulations in condensed matter physics may be achieved using various different simulator systems. Examples of that include (a) atoms in optical lattices, (b) one-dimensional arrays of cavities, (c) two-dimensional arrays of cavities with atoms. With ions one can create (d) ions in linear chains, (e) two-dimensional arrays of planar traps, (f) two-dimensional Coulomb crystals and with electrons we may build simulators in the form of (g) electrons in quantum dot arrays created by a mesh gate, (h) arrays of superconducting circuits or electrons trapped on the surface of liquid helium. For all these systems, the average inter-particle distances range between the 0.1µm and 10µm orders of magnitude.