Browsing posts in: quantum computing

Introduction to quantum computing with Q# – Part 8, Superdense coding

Last time, we discussed the quantum teleportation protocol, which relies on the phenomenon of quantum entanglement to move an arbitrary quantum state from one qubit to another, even if they are spatially separated. Today, we shall continue exploring the scenarios enabled by entanglement, by looking at the concept called “superdense coding”. It allows sending two classical bits of information by physically moving only a single qubit around, and is sometimes referred to as a conceptual inverse of teleportation.

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Introduction to quantum computing with Q# – Part 7, Quantum state teleportation

In the previous part of the series we discussed how quantum theory prohibits copying of an arbitrary quantum state. In computing terms, this means that regardless of the richness of features provided by high-level quantum-specific languages such as Q#, we cannot implement a classical functionality of copy-and-paste on a quantum computer.

It turns out, however, that we can achieve a cut-and-paste type of effect, through a remarkable process of quantum teleportation.

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Introduction to quantum computing with Q# – Part 6, No-cloning theorem

In the last part of this series we looked at the phenomenon of entanglement – one of the core concepts of quantum theory, which has been fundamentally important in the development of quantum information theory. We grappled with its deeply mysterious behavior and tried to understand and project its consequences onto the Q# code.

In today’s part 6, we shall ask ourselves a seemingly innocent question – how to you clone a quantum state, or in other words, how do you copy a qubit?

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Running Q# compiler and simulation programmatically from a C# application

The QDK provides an excellent, low barrier way of getting started with Q# development – without having to deal with the compiler directly, or worrying about how to simulate the code you wrote on a classical device. Additionally, for more technically versed users, the Q# compiler is also available as a command line utility that can be used to fine tune the compilation experience and cater to complex scenarios. The QDK is well documented, and the command line compiler provides good documentation as part of the application itself, but one of the things that is not widely known is that the Q# compiler can also be easily used programmatically – via its Nuget package.

Let’s have a look.

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Introduction to quantum computing with Q# – Part 5, Entanglement

In the last post in this series we dove deep into the mathematics and usage examples of multi-qubit gates, with special attention paid to one of the most critical gates in quantum computing, the CNOT gate.

In today’s post we are going to explore the wonders of entanglement – a core concept of quantum mechanics and a critical idea for quantum computing, where it is obtained via the application of the CNOT gate.

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Introduction to quantum computing with Q# – Part 4, multi-qubit gates

In the previous post of this series, we discussed single qubit gates. In this next instalment, we are going to explore gates that act on multiple qubits at once, thus completing the exploration of quantum circuit building. We are also going to slowly, but diligently uncover the underlying theoretical scheme towards one of the most bizarre concepts in quantum mechanics – entanglement, which is something that will be dedicating the next part to.

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Intro to quantum computing with Q# – Part 1, The background and the qubit

Quantum mechanics is one of the fundamental theories of physics, and has been tremendously successful at describing the behavior of subatomic particles. However, its counter-intuitive probabilistic nature, bizarre rules and confusing epistemology have troubled some of the greatest physicists of the 20th century, even prompting Albert Einstein to remark “Old Man (often translated as 'God') doesn't play dice”.

Today, we are at the dawn of the quantum computing age, a multidisciplinary field that sits at the intersection of quantum physics, computer science, mathematics and chemistry and may revolutionize the world of computing and software engineering.

In this post I am starting a new series that will, through the lens of a .NET developer, introduce the basics of quantum computing – using examples in Q#.

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