Supercomputer simulates QC with 42 qubits

JUGENE simulates a quantum computer with 42 qubits. That may not sound impressive to those not familiar with simulating quantum computers, but it is pretty remarkable they could do that many qubits. To simulate an arbitrary quantum state requires a matrix of 2^n complex numbers to simulate n qubits. For 42 qubits that is 4,398,046,511,104 complex numbers.

Given this exponential growth, it wasn't too surprising that I ran into size constraints quickly when working on Cove. For the following example I did a simple case of putting the entire register in superposition, then measuring it. This was done on an Intel Core Duo T2300 with 1 GB of RAM maybe a year and a half ago. The jump between 9 and 10 qubits really illistrates how the exponential slow down happens in a simulation of an arbitrary quantum system.