Measuring central charge on a universal quantum processor.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 41507148.
- Also identified by DOI 10.1038/s41467-025-66775-9 and PMC identifier 12789439.
- Licence recorded as CC BY-NC-ND.
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Abstract
Central charge is a fundamental quantity in conformal field theories (CFT), and plays a crucial role in determining universality classes of critical points in two-dimensional systems. Despite its significance, the measurement of central charge has remained elusive thus far. In this work, we present the experimental determination of the central charge using a universal quantum processor. Using a classically optimized variational quantum circuit and employing advanced error mitigation techniques, we successfully prepare ground states of various 1 + 1D quantum spin chain models at their critical point. Leveraging the heavy-hex structure of IBM quantum processors, we are able to implement periodic boundary conditions and mitigate boundary effects. We then extract the central charge from the scaling behavior of the sub-leading term of Rényi generalizations of classical Shannon entropy, computed for local Pauli measurements in the conformal bases (σ<sup>z</sup> and σ<sup>x</sup>). The experimental results are consistent with the known central charge values for the transverse field Ising (TFI) chain (c = 0.5) and the XXZ chain (c = 1), achieving relative errors as low as 5 percent.