Quantum Error Correction

Because things do not always go as planned

Quantum computing is a marvel of modern science, promising to solve problems that no classical computer could ever tackle. But at the heart of this technology lies a paradox: quantum systems, by their very nature, are fragile.

This fragility is why Quantum Error Correction (QEC) isn’t just an option for quantum computers; it’s a necessity. Without it, the quantum revolution would remain a theoretical dream. Pasqal, a leader in neutral-atom quantum computing, has made error correction a core part of its mission. By leveraging the unique advantages of neutral-atom qubits, Pasqal is tackling one of the most formidable challenges in quantum computing: ensuring that quantum information remains accurate and reliable even in the face of noise and decoherence.

Calculations performed on QPUs can be erroneous…

Just like any computer (quantum or not) but, for Quantum, the problem is bigger.

On average, a Central Processing Unit (CPU) has an error rate of 0.000000000000001 % per operation.

For a Quantum Processing Unit it goes up to 0,1% per operation.

1000 operations, 1 error

The reasons for these errors

To avoid (or at east reduce) the errors, we need to understand why it happens.
There are four main causes for errors.

Laser Imperfection

From an imperfect control of the system

Interferences

From electromagnetic or environmental noise.

Superposition

A quantum object can be in two different states at the same time.

Entanglement

Two quantum objects cannot be independantly described.

What can be done about it ?

Quantum Computers being “Quantum”, there’s not much we can do about their “Quantumness” and the errors it creates. However, we can act on the system itself in order to mitigate those errors.

This is Fault-Tolerant Quantum Computing (FTQC)