Category: Quantum Error Correction

Noise, decoherence, and imperfections in quantum gates can cause errors in quantum computations. Current state-of-the-art quantum computers have error rates that are typically in the range of 1% to 0.1%.

Quantum theory is the theoretical basis of modern physics that explains the nature and behavior of matter and energy on the atomic and subatomic level. The nature and behavior of matter and energy at that level is sometimes referred to as quantum physics and quantum mechanics.

Einstein’s paper, “Can Quantum-Mechanical Description of Physical Reality Be Considered Complete?” prompted Niels Bohr to write a rebuttal. Modern experiments have upheld Quantum Theory despite Einstein’s objections. However, the EPR paper introduced topics that form the foundation for much of today’s physics research.

In fact, the difficulty of correcting both bit-flip and phase-flip errors is one reason why error correction is much harder for quantum computers than for classical computers. Figure 1. Three types of errors affecting qubits: (1) bit-flip errors, (2) phase-flip errors, and (3) erasure errors

Out of the three strategies, quantum error mitigation is of most interest to quantum coders. Error suppression and error correction take place at the hardware level, whereas error mitigation is applied classically after a circuit has executed.

Error correction is a process by which students have to identify the error/mistake in a sentence and convert it into a grammatically correct sentence.

Phase Flip Errors (Dephasing): These occur when a qubit loses its phase information due to environmental disturbances. Bit Flip Errors (Depolarization): Environmental factors like thermal vibrations can cause qubits to flip states, leading to computational inaccuracies.

Correcting errors in the qubits poses special challenges.

Quantum error correction protects quantum information against environmental noise. When using qubits, a measure of quality of a code is the maximum number of errors that it is able to correct.

Quantum Error Correction (QEC) refers to a set of techniques used to protect quantum information from errors due to decoherence and other quantum noise. Unlike classical error correction, where bits are either 0 or 1, quantum error correction must deal with qubits that can exist in superpositions of states.