



@article {2252,
	title = {Verified Quantum Information Scrambling},
	year = {2018},
	abstract = {<p>Quantum scrambling is the dispersal of local information into many-body quantum entanglements and correlations distributed throughout the entire system. This concept underlies the dynamics of thermalization in closed quantum systems, and more recently has emerged as a powerful tool for characterizing chaos in black holes. However, the direct experimental measurement of quantum scrambling is difficult, owing to the exponential complexity of ergodic many-body entangled states. One way to characterize quantum scrambling is to measure an out-of-time-ordered correlation function (OTOC); however, since scrambling leads to their decay, OTOCs do not generally discriminate between quantum scrambling and ordinary decoherence. Here, we implement a quantum circuit that provides a positive test for the scrambling features of a given unitary process. This approach conditionally teleports a quantum state through the circuit, providing an unambiguous litmus test for scrambling while projecting potential circuit errors into an ancillary observable. We engineer quantum scrambling processes through a tunable 3-qubit unitary operation as part of a 7-qubit circuit on an ion trap quantum computer. Measured teleportation fidelities are typically \&sim;80\%, and enable us to experimentally bound the scrambling-induced decay of the corresponding OTOC measurement.</p>},
	url = {https://arxiv.org/abs/1806.02807},
	author = {Kevin A. Landsman and Caroline Figgatt and Thomas Schuster and Norbert M. Linke and Beni Yoshida and Norman Y. Yao and Christopher Monroe}
}
