The team of scientists of France and China have deepened the understanding of quantum contextuality and have studied its potential properties.
The concept of contextuality plays a significant role in quantum calculations and offers potential advantages compared to conventional calculations. In classical physics, measurement simply reveals the existing properties of an object. However, in quantum mechanics, measurement can actually change the condition of the quantum system, and the result depends on other calculations made within it.
In a study published in the Physical Review Letters, scientists focused on the Bell non-linearity of a single quantum system. Bell non-linearity is a fascinating phenomenon of quantum mechanics associated with quantum entanglement. It states that measurements made on entangled particles can be correlated, even if they are performed simultaneously at a considerable distance from each other.
The researchers utilized a specially designed spatial modulation technique to accurately prepare and observe the state of the particles. One method to represent quantum states is through the coding of the spatial mode of photons.
During the experiment, an unexpected phenomenon was discovered. The obtained results exceeded the anticipated values by 68 standard deviations. The data did not align with the expected behavior of particles, which rarely occurs by chance.
The deviation was observed in the analysis of non-contextuality inequality. Non-contextuality inequalities are mathematical formulas that should hold true if measurements are independent of the context (i.e. other dimensions). The inconsistency in the inequalities discovered by the scientists indicates the presence of contextuality, which is a unique characteristic of quantum systems.
Ultimately, the experiment reached a new record in the degree of contextuality. This was determined by comparing the level of contextuality in the local system with the maximum values that can be achieved. The ratio reached 0.274, which is the highest result for single-particle experiments.
Thus, the researchers not only demonstrated the presence of quantum contextuality but also paved the way for further investigation into this phenomenon and its potential applications in calculations. This discovery, according to the scientists, “provides a foundation for observing more quantum correlations and has the potential to advance the implementation of quantum calculations in various physical systems.”