Researchers at UNSW have successfully materialized a famous quantum thought experiment. Their findings pave the way for more robust quantum calculations, with major implications for error correction, a key obstacle in the development of quantum computers.
Quantum mechanics has intrigued scientists for over a century. The 'Schrödinger's cat' thought experiment illustrates a quantum superposition state, where a cat is simultaneously alive and dead, depending on the decay of a radioactive atom.
Professor Andrea Morello's team used an antimony atom, far more complex than standard qubits, to conduct this experiment. Published in
Nature Physics, this research shows how antimony, with its eight spin directions, offers a new perspective on quantum superposition.
Lead author Xi Yu explains that antimony allows for superposition on a larger scale, compared to a cat having seven lives. This robustness against errors is crucial for quantum computing.
The antimony atom is integrated into a silicon quantum chip, a promising technology for the scalability of quantum computers. This advancement enables better detection and correction of errors, essential for the development of this technology.
Professor Morello emphasizes the importance of this discovery for quantum error correction, a major challenge in quantum computing. This research is the result of an international collaboration, combining theoretical and experimental expertise.
From left to right: Benjamin Wilhelm, Xi Yu, Prof Andrea Morello, Dr. Danielle Holmes.
Credit: UNSW Sydney
This study marks a significant step towards the realization of reliable quantum computers, offering a new method to encode and protect quantum information against errors.
What is quantum superposition?
Quantum superposition is a fundamental principle of quantum mechanics, stating that a particle can exist in multiple states simultaneously. Unlike classical physics, where an object has a defined position and state, in quantum mechanics, a particle can be in a superposition state, such as being both 'here' and 'there'.
This concept is illustrated by the Schrödinger's cat thought experiment, where a cat is both alive and dead until an observation is made. Quantum superposition is essential for understanding quantum phenomena and is the foundation of quantum technologies, such as quantum computers.
In the context of this research, the use of an antimony atom allows for the creation of quantum superposition on a larger and more complex scale than traditional qubits, opening new avenues for quantum computing.
How does quantum error correction work?
Quantum error correction is a set of techniques aimed at protecting quantum information from errors due to decoherence and quantum noise. Unlike classical bits, qubits are extremely sensitive to their environment, which can lead to errors in quantum calculations.
Quantum error correction relies on encoding quantum information redundantly, allowing for the detection and correction of errors without disturbing the quantum state. This involves the use of quantum codes, which can detect errors by measuring specific properties of qubits without directly observing them.
In this research, the use of an antimony atom with eight spin directions offers greater robustness against errors, as multiple consecutive errors are required to alter the quantum information. This represents a significant advancement in the development of reliable quantum systems.