Fig. 4: QIM enables 6-qubit QSS.

a We share six eigenstates of three Pauli matrices into a 6-qubit hyperentangled system and show the trace distance of the reduced density matrix of each qubit from the maximally mixed state. b The experimental results of unmasking. We pass each of the six initial states to six different qubits and display the fidelity of each process. The error bar indicates 1 standard deviation (obtained from the Poissonian statistics of the detected four-photon counts).