Experimental preparation and verification of quantum money

Abstract

A quantum money scheme enables a trusted bank to provide untrusted users with verifiable quantum banknotes that cannot be forged. In this work, we report a proof-of-principle experimental demonstration of the preparation and verification of unforgeable quantum banknotes. We employ a security analysis that takes experimental imperfections fully into account. We measure a total of $3.6\ifmmode\times\else\texttimes\fi{}{10}^{6}$ states in one verification round, limiting the forging probability to ${10}^{\ensuremath{-}7}$ based on the security analysis. Our results demonstrate the feasibility of preparing and verifying quantum banknotes using currently available experimental techniques.