I’m not happy with all the analyses that go with just the classical theory,because Nature isn’t classical, dammit, and if you want to make a simulationof nature, you’d better make it quantum mechanical, and by golly it’s awonderful problem, because it doesn’t look so easy.
It’s not a Turing machine, but a machine of a different kind.
Despite the incredible power of today’s supercomputers, many complex computing
problems cannot be addressed by conventional systems. The huge growth of data and
our need to better understand everything from the universe to our own DNA leads
us to seek new tools that can help provide answers. Quantum computing is the next
frontier in computing, providing an entirely new approach to solving the world’s
most difficult problems.
While certainly not easy, much progress has been made in the field of quantum
computing since 1981, when Feynman gave his famous lecture at the California
Institute of Technology. Still a relatively young field, quantum computing is
complex and different approaches are being pursued around the world. Today, there
are two leading candidate architectures for quantum computers: gate model
(also known as circuit model) and quantum annealing.
Gate-model quantum computing
implements compute algorithms with quantum gates, analogously to the use of Boolean
gates in classical computers.
With quantum annealers you initialize the system in a low-energy state and
gradually introduce the parameters of a problem you wish to solve. The slow change
makes it likely that the system ends in a low-energy state of the problem, which
corresponds to an optimal solution. This technique is explained in more detail in
the What is Quantum Annealing? chapter.
Quantum annealing is implemented in D-Wave’s generally available quantum computers,
such as the Advantage™, as a single quantum algorithm, and this
scalable approach to quantum computing has enabled us to create quantum processing
units (QPUs) with more than 5000 quantum bits (qubits)—far beyond the state of
the art for gate-model quantum computing.
D-Wave has been developing various generations of our “machine of a different kind,”
to use Feynman’s words, since 1999. We are the world’s first commercial quantum
computer company.
The D-Wave system contains a QPU that must be kept at a temperature near absolute
zero and isolated from the surrounding environment in order to behave quantum
mechanically. The system achieves these requirements as follows:
Cryogenic temperatures, achieved using a closed-loop cryogenic dilution
refrigerator system. The QPU operates at temperatures below 20 mK.
Shielding from electromagnetic interference, achieved using a radio frequency
(RF)–shielded enclosure and a magnetic shielding subsystem.
The D-Wave QPU (Figure 2) is a lattice of tiny metal loops,
each of which is a qubit or a coupler. Below temperatures of 9.2 kelvin, these
loops become superconductors and exhibit quantum-mechanical effects.
The QPU in D-Wave’s Advantage system has more than 5,000 qubits and
35,000 couplers. To reach this scale, it uses over 1,000,000 Josephson
junctions, which makes the Advantage QPU by far the most complex superconducting
integrated circuit ever built.
For more details on the physical system, including specifications and
essential safety information required for anyone who accesses the hardware
directly, see the D-Wave Quantum Computer Operations manual, available from D-Wave.
Users interact with the D-Wave quantum computer through a web user interface (UI),
and through open-source tools that communicate with the Solver API (SAPI).[1]
The SAPI components are responsible for user interaction, user authentication,
and work scheduling. In turn, SAPI connects to back-end servers that send problems
to and return results from QPUs and additional solvers, which are located in
different geographical regions (for example, North America or Europe).[2]
See Figure 3 for a simplified view of the D-Wave software
environment.
Leap™ is the quantum cloud service from D-Wave Systems.
Learn about the types of problems that the D-Wave quantum computer can solve,
run interactive demos and coding examples on the system, contribute your coding
ideas, and join the growing conversation in our community of like-minded users.
D-Wave’s Python-based open-source software development kit (SDK), Ocean, makes
application development for quantum computers rapid and efficient and facilitates
collaborative projects.
See Ocean SDK on GitHub to access the
Ocean SDK, and Ocean documentation for
the associated documentation.
