Experimental data for "Quantum simulation of Hawking radiation and curved spacetime with a superconducting on-chip black hole"

We simulate both flat and curved spacetimes in a 1D array of 10 superconducting qubits with tunable couplers. The experimental data of Figure 2 shows the quantum walks in flat and curved spacetimes with four different initial states. The quantum walks of quasi-particle in the curved spacetime reflect the gravitational effect near the black hole, resulting in the behaviour of Hawking radiation. By virtue of the state tomography measurement of all 7 qubits outside the analogue event horizon, we show that the stimulated Hawking radiation can be verified. The experimental data of Figure 3 includes the density matrix of the 7 qubits and the radiation probabilities. In addition, an entangled pair is prepared inside the horizon. The entanglement evolutions of flat and curved spacetime are compared in Figure 4. Our results would stimulate more interests to explore the related features of black holes using the programmable superconducting processor with tunable couplers.