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# Tag Info

### Which subatomic particle does each company use in quantum computing?

Google, IBM and Rigetti use transmon qubits; these are basically fancy LC circuits where a Josephson junction and capacitor connect two superconducting islands. Because of this, they are also often ...
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### Is there proof that the D-wave (one) is a quantum computer and is effective?

There is still a search for problems where the D-Wave shows improvement over classical algorithms. One might recall media splashes where the D-Wave solved some instances $10^8$ times faster than a ...
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### How do you write a simple program for a D-Wave device?

The 'Hello World' equivalent in the D-Wave world is the 2D checkerboard example. In this example, you are given the following square graph with 4 nodes:        &...
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### How do you write a simple program for a D-Wave device?

The inputs to the D-Wave are a list of interactions and more recently the annealing time of the qubits. As you mentioned the Ising problem is one of the easiest with $J_{ij} = 1$ in the problem ...
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### How are IBM's 127 qubits more potent than the 5760 qubits D-Wave - Advantage_system6.1?

As the other answers have stated, they're two substantially different systems that are unfortunately both marketed as quantum computers. D-Wave is more specifically a quantum annealer. At a high level,...
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### What is D-Wave's "Pegasus" architecture?

Pegasus is the first fundamental change in D-Wave's architecture since the D-Wave One. The D-Wave Two, 2X, and 2000Q all used the "Chimera" architecture, which consisted of unit cells of $K_{4,4}$ ...
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### Why D-Wave 2000Q requires such a low pressure?

The device works at cryogenic temperatures, which is so cold that all the gasses would freeze on the experiment device. Moreover, before they do so, they would conduct heat from the walls of the ...
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### What would be the simplest addition that would make the D-Wave architecture universal?

XX couplers are necessary to make an quantum annealing universal. https://arxiv.org/abs/0704.1287 As for fabricating them, I’m not too familiar with the hardware issues. Perhaps someone else can ...
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### When and where was the first use of the term Chimera?

The earliest non-internal reference I can find is in NIPS 2009 from a Google/D-Wave effort1. You'll notice that the two Choi papers, in addition to not using the term "Chimera", do not describe a ...
Accepted

### What is the problem in demonstrating quantum supremacy?

D-Wave's 2000Q is a quantum annealer, not a circuit-based quantum computer like Google's Sycamore. The qubits in D-Wave's system are much noisier, less controlled and perform a fundamentally ...
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### Moore's law for quantum computers

Moore's law deals with the number of transistors in an integrated circuit, which is used as a proxy for computational power. In a quantum computing device the analogy would be the number of qubits. ...
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### What precisely is Reverse Annealing?

Until recently, D-Wave's quantum annealing devices always started from a uniform superposition over all $N$ qubits:               ...
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### Why did D-Wave choose the Chimera graph the way they did?

You are right that $K_{3,3}$ is non-planar, but as you said yourself, a larger $k$ is much better. If they could do $K_{1000,1000}$ that would be nice, because each qubit could be coupled to 1002 ...
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