Fault-tolerant Quantum Computing
- [University of Oxford]
- Overview
Fault-tolerant quantum computing (FTQC) is the ability of quantum computers to perform calculations with low logical error rates.
FTQC is essential because:
- Noisy Intermediate-Scale Quantum (NISQ) computers: Can return noise after a few gates are applied to a small number of qubits.
- Quantum computer simulators: Can't usually simulate more than 40 qubits.
FTQC builds on quantum error correction and denotes techniques that allow computations to be performed on a quantum system with faulty gates as well as storage errors.
The threshold theorem (or quantum fault-tolerance theorem) states that a quantum computer with a physical error rate below a certain threshold can, through application of quantum error correction schemes, suppress the logical error rate to arbitrarily low levels.
Quantum fault-tolerance essentially is avoiding the uncontrollable cascade of errors caused by the interaction of quantum-bits.
- Photonic-based Fault-tolerant Quantum Computing
A photonic-based fault-tolerant quantum computer uses photons to encode and manipulate qubits. Photons are ideal for fault-tolerant quantum computation because they are resistant to noise and decoherence.
Photonic quantum computers calculate by sending photons through optical elements that represent the algorithm. They use quantum optics techniques to execute quantum algorithms and protocols with improved efficiency.
<More to come ..>
