What is "Modern Quantum Simulation" experimentation?

[Gerinski]

Hi all,

In this paper they mention that the "experiments" were done using "quantum simulation". Expressions like the following are used:

"Here we experimentally simulate the nonlinear behaviour of a qubit..."

"Modern experimental quantum simulation allows one to ask meaningful questions that provide insights into the behaviour of complex quantum systems"

"Our experimental simulation of a qubit in the pure state..."

"Quantum simulation is a versatile and powerful tool for investigating quantum systems that are hard or even impossible to access in practice"

http://www.nature.com/articles/ncom...&tracking_referrer=www.scientificamerican.com

What is such a "quantum simulation experiment"? Is it a real physical experiment? Or a computer simulated one? How can be quantum behaviour simulated not using a quantum computer or quantum process? Is it about modelling, or mapping, a complex quantum process into some simpler physical quantum system such as studying photons polarization behaviour? If so, how confident can we be that such simple models provide a reliable mapping for the way more complex systems behave?

TX

 

[f95toli]

The principle is very similar to an analogue computer. Before digital computers became commonplace analogue computers were (and in some cases still are) used in many applications that requires fast solution of mathematical problems (in.e.g. control system for aircraft). The idea is to create one system that is mathematically equivalent to another. The most common case was to create analogue electrical circuits (using capacitors, inductors etc) that were arranged in such a way that the differential equations that governed their behaviors were identical to the behavior of some mechanical system you wanted to simulate.

Quantum simulators work in the same way. The idea is to create a "simple" controllable system that is mathematically identical (in the simplest case it might have the same effective Hamiltonian) to some other more complicated (and not easily controlled) system you want to simulate.