Quantum computers have shown a new way to compute old problems. D-Wave  has a quantum annealer, and <a href="https://en.wikipedia.org/wiki/D-Wave_Two">Wikipedia</a> describes the D-Wave quantum computer and its use of quantum annealing properties. Hardware wise, how does D-Wave achieve quantum annealing? 

There may be many ways to achieve quantum annealing. D-Wave, being first on the market with quantum annealing hardware, therefore is open to more scrutiny (is their hardware open to such scrutiny?) Does D-Wave use a specific type of annealing at the atomic level (there could be one of many ways to achieve quantum annealing), or (in other words) are there many ways to achieve quantum annealing?