Figure 1

From: Preserving entanglement during weak measurement demonstrated with a violation of the Bell–Leggett–Garg inequality

Figure 1
Figure 1

Schematic of the hybrid Bell–Leggett–Garg inequality and optical micrograph of the superconducting quantum device. The algorithm consists of two LGI weak measurement branches, bridged by the entanglement of the central Bell qubits. The Bell pair (β1,2) is initially prepared in the anti-symmetric singlet Bell state |Ψ. Next, each Bell qubit is rotated to its first measurement basis (a or b) and entangled with its ancilla qubit (α1,2). Finally, the Bell qubits are rotated and projectively read out in bases corresponding to angles a′ and b′. By correlating the final projective readout and the weak ancilla measurements, we calculate all four terms of a CHSH correlator simultaneously.