In a groundbreaking achievement, researchers at Quantinuum, a leading quantum computing company, have successfully teleported a logical qubit using fault-tolerant methods. This landmark study, published in Science, represents a significant step towards the realization of a truly reliable and scalable quantum computer.
Quest for Quantum Supremacy
One of the major problems in quantum computing has to do with errors. Quantum systems are notoriously delicate, and the tiniest amount of noise can lead to errors that sap the computational power from calculations. One way in which researchers are trying to address this problem: the idea of so-called logical qubits — quantum bits that are spread among several physical qubits, making them less likely to be influenced by noise and errors.
What that means is that (emphasis on the term testing): researchers at Quantinuum have successfully teleported the first-ever logical qubit to be passed through fault-tolerant tests. The discovery introduces the possibility for constructing more reliable and fault-tolerant quantum computers, which would allow us to perform work that is truly beyond what classical computing can achieve.
Transversal versus Lattice Surgical Approaches
Using two different techniques that they called transversal and lattice surgery, the team at Quantinuum was able to pull this off.
The a transversal and function of operations on more than one qubit simultaneously, thus providing another way to control the teleportation process and speed it up. Instead the lattice surgery technique aimed to achieve operations by moving qubit boundaries, which made these techniques more hardware-agnostic compared to other approaches in quantum computing.
The lattice surgery method was demonstrated to be just as effective as the transversal method in relocating logical qubits, but had slightly lower fidelity due to the imperfections of quantum operations. Still, the successful teleportation of logical qubits using fault-tolerant techniques is a notable step forward for quantum computing.
Inband In-Memory Error Correction: The Secret of Fault Tolerance
An important part of this development is the application in real-time decoding and error correction by researchers. Through the use of the Steane code, they were able to perform error correction at four separate times during the teleportation process to protect the logical qubit against errors from occurring during teleportation.
We take this real-time error correction to be a basic primitive necessary for fault-tolerant quantum computation. The successful teleportation of a logical qubit with such high fidelity shines light on our path towards building a scalable and fault-tolerant quantum computer, from the Quantinuum team.
This milestone goes far beyond the immediate technological achievements. It marks a major milestone in the quest for quantum supremacy, or the ability of quantum computers to perform some calculations faster than classical computers. This represents a huge breakthrough, as it clears the path for entering the era of truly transformational quantum computing better than before.
