Following up on Sunday's Computing: "‘The next quantum breakthrough will happen in five years".
From EE Times, February 1:
Development of quantum computers has advanced steadily over the last decade, spurred by the promise of harnessing the unique properties of quantum physics: qubits, or quantum bits, exist as either 0s, 1s or simultaneously as a zero and one.
Multiple companies now offer quantum applications as a service via cloud platforms such as Amazon Web Services, Google Cloud and Microsoft Azure.
Development is led by established companies and startups. An earlier column on quantum computing surveys the field. Here we provide an overview and perspectives on the status of quantum technologies.
For background, a U.S. Government Accountability Office (GAO) report examines the status and prospects for quantum computing. This post draws heavily on the GAO report.
An excellent overview of quantum computers by our colleague Maurizio Di Paolo Emilio is here.
Multiple technologies are required to deploy quantum computers, making it harder to predict when the technology will be practical. As the pace of development accelerates, many experts remained convinced practical quantum computers are still at least a decade away.
Analog vs. qubit-gate
Physical qubits, or quantum bits, are the basic building block. There are two main quantum computing methods: analog and gate-based quantum computers. The table below summarizes the differences between the two technologies.
(Click on image to enlarge.)
Physical qubits include naturally-occurring particles and artificial structures. The former includes atoms, trapped ions and photons. Trapped ions and photons are the leading technologies for this segment.
Artificial physical qubits simulate naturally occurring particles, creating qubit gates. Quantum gates are similar to logic gates in conventional computers.
This category includes superconducting circuits, quantum dots and crystal defects. An example is a nitrogen atom within a diamond’s carbon lattice, which is called a color center. Superconducting circuits dominate this category.
In designing quantum computers from qubits, technology has been developed to manipulate quantum properties and entangle multiple qubits with one another. These manipulations are accomplished with lasers, microwaves, electric or magnetic fields and other methods. Examples are listed at the bottom of the table above.
Quantum challenges
Steady progress may soon yield quantum machines with thousands of qubits and approaching 1 million qubits after 2030. Such advances will greatly expand deployment by cloud services providers, academic institutions and corporations.
The next table summarizes the challenges facing quantum developers. The lower section outlines deployment challenges.....
....MUCH MORE
