Is Quantum Computing Really a Thing?

What is the qubit?

• Two-state quantum-mechanical system, such as the polarization of a single photon
• Two possible outcomes for the measurement of qubit – 1 and 0
• Quantum mechanics tells us the state of a qubit is unknown until it is observed
• Before the observation, the state is a “probability space”
• The Bloch sphere describes probability, NOT absolute values

More details: https://en.wikipedia.org/wiki/Qubit

Quantum computation vs classical computation

• Quantum circuits hold exponentially more information at any given point for the same logic circuit size
• Quantum makes problems that are insoluble classically solvable in a reasonable time
• Quantum computers cannot meaningfully persist state
• The physical limitations of hardware limit the breadth and depth of programs
• Quantum computers are hard to program

IBM Q Experience

https://quantumexperience.ng.bluemix.net/qx/experience

• Public access quantum computer
• Easy to set up
• Execute programs on real 5 qubit quantum computer
• Can compose quantum scores and persist them
• Execute programs on a real

Microsoft Quantum Development Kit

https://docs.microsoft.com/en-us/quantum/index?view=qsharp-preview

• Tools to build own quantum computing programs and experiments
• Visual Studio support
• Q# – the domain-specific programming language used for expressing quantum algorithms.
• A full state vector simulator optimized for accurate vector simulation and speed

Extras

Introducing QC2 – the Quantum Compute Cloud (Amazon):

https://aws.amazon.com/blogs/aws/introducing-qc2-the-quantum-compute-cloud/

Google moves toward quantum supremacy with 72-qubit computer:

https://www.sciencenews.org/article/google-moves-toward-quantum-supremacy-72-qubit-computer