As InfoQ reported, Microsoft announced its plans to build a quantum computer at its Ignite conference and promised a development kit for it. Now, the Microsoft Quantum Development Kit has become available as a free preview.
Sporting integration with Visual Studio, the Quantum Development Kit includes the Q# programming language and a quantum simulator which Microsoft says is able to simulate up to 30 logical qubits on a typical laptop. 30 logical qubits require about 16GB to simulate. To get from there to a 40 logical qubit simulator, a 2^10 increase in memory is required, and Microsoft is offering an Azure-based simulator providing as much. Developers can use the Quantum Development Kit to learn how to program quantum computers while waiting for Microsoft topological quantum computer, according to Microsoft, which also claims that programs written using the simulator will run unmodified on the real quantum computer as well.
The main idea behind Microsoft quantum processor is the topological qubit, which does not store its information in a specific place. Instead, it is stored globally, within its topological structure, like it happens with a string, which you can say whether it is knotted or not only by looking at the whole picture and not to any of its local properties. The main advantage of this approach to quantum information representation is requiring a minor amount of error correction, which becomes a limiting factor when it comes to scaling quantum processors.
On the programming side, Microsoft describes Q# as a domain-specific programming language with a native type system for qubits, operators, and other abstractions. It includes support for both classical language control and quantum algebra.
The following is an example of a Q# program that is able to set a qubit in a given state by looking at it and, if it is not in the required state, by flipping it:
namespace Quantum.Bell {
open Microsoft.Quantum.Primitive;
operation Set (desired: Result, q1: Qubit) : () {
body {
let current = M(q1);
if (desired != current) {
X(q1);
}
}
}
}
Q# integration with the Visual Studio debugger allows to set breakpoints and step into code, as well as to estimate the resources required to execute a quantum program through the trace simulator.
Along with the Kit, Microsoft is also releasing comprehensive documentation which covers from the basics of quantum computing to more advanced concepts such as managing quantum machines and drivers, and specific development techniques.
You can download the Microsoft Quantum Development Kit to start using it. It requires Visual Studio 2017, which is also available as a Community Edition for free.
