Listen to Professor Jan-Åke Larssons talk at the Cavendish Quantum Information Seminar Series, on what gives advantages to quantum algorithms.
Video

The seminar with the title “Quantum computation and the additional degrees of freedom in a physical system” was held this fall.

The speed-up of Quantum Computers is the current drive of an entire scientific field with several large research programmes both in industry and academia world-wide. Many of these programmes are intended to build hardware for quantum computers.

A related important goal is to understand the reason for quantum computational speed-up; to understand what resources are provided by the quantum system used in quantum computation. Some candidates for such resources include superposition and interference, entanglement, nonlocality, contextuality, and the continuity of state-space. The standard approach to these issues is to restrict quantum mechanics and characterize the resources needed to restore the advantage.

Our approach is dual to that, instead extending a classical information processing systems with additional properties in the form of additional degrees of freedom, normally only present in quantum-mechanical systems.

In this talk, we will have a look at these additional degrees of freedom including the effect of Pauli-group contextuality, and how quantum computers make use of them to achieve the quantum speedup.

Publications
[1] Christoffer Hindlycke, Jan-Åke Larsson, An efficient contextual ontological model of n-qubit stabilizer quantum mechanics, to appear in Phys Rev Lett (2022). https://arxiv.org/abs/2202.05081
[2] Niklas Johansson, Felix Huber, Jan-Åke Larsson, Conjugate Logic (2021). https://arxiv.org/abs/2102.06572
[3] Niklas Johansson, Jan-Åke Larsson, Quantum Simulation Logic, Oracles, and the Quantum Advantage, Entropy 21:800 (2019). https://dx.doi.org/10.3390/e21080800

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Jan-Åke Larsson.

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