# Computing with a single qubit faster than the computation quantum speed limit

## TL;DR

This paper shows that under energy constraints, a single qubit can be used to perform faster computations than the quantum speed limit by leveraging nonorthogonal states, without entanglement.

## Contribution

It introduces a method to accelerate quantum computations using nonorthogonal states of a single qubit under energy constraints, bypassing traditional quantum correlations.

## Key findings

- Single qubit can outperform quantum speed limit with energy constraints.
- Nonorthogonal states enable faster information processing.
- Error correction strategies can protect such quantum computations.

## Abstract

The possibility to save and process information in fundamentally indistinguishable states is the quantum mechanical resource that is not encountered in classical computing. I demonstrate that, if energy constraints are imposed, this resource can be used to accelerate information-processing without relying on entanglement or any other type of quantum correlations. In fact, there are computational problems that can be solved much faster, in comparison to currently used classical schemes, by saving intermediate information in nonorthogonal states of just a single qubit. There are also error correction strategies that protect such computations.