Measurement-induced entanglement and teleportation on a noisy quantum processor
Google Quantum AI and Collaborators, Jesse C. Hoke, Matteo Ippoliti, Eliott Rosenberg, Dmitry A. Abanin, Rajeev Acharya, T. I. Andersen, M. Ansmann, Frank Arute, Kunal Arya, Abraham Asfaw, Juan Atalaya, Joseph C. Bardin, Andreas Bengtsson, Gina Bortoli, Alexandre Bourassa, Jenna Bovaird, L. Brill, M. Broughton, B. B. Buckley, D. A. Buell, Tim Burger, Brian Burkett, Nicholas Bushnell, Z. Chen, B. Chiaro, D. Chik, J. Cogan, Roberto Collins, P. Conner, William Courtney, A. L. Crook, Ben Curtin, Alejandro Grajales Dau, D. M. Debroy, Alexander Del Toro Barba, Sean Demura, Agustín Di Paolo, Ilya Drozdov, A. Dunsworth, Daniel Eppens, Catherine Erickson, Edward Farhi, Reza Fatemi, V. S. Ferreira, Leslie Flores Burgos, Ebrahim Forati, A. G. Fowler, Brooks Foxen, William Giang, Craig Gidney, D. Gilboa, Marissa Giustina, Raja Gosula, Jonathan A. Gross, Steve Habegger, M. C. Hamilton, M. Hansen, Matthew P. Harrigan, Sean D. Harrington, P. Heu, M. R. Hoffmann, Sabrina Hong, Trent Huang, Ashley Huff, William J. Huggins, S. V. Isakov, Justin Iveland, E. Jeffrey, Jiang Zhang, C. Jones, Pavol Juhás, Dvir Kafri, K. Kechedzhi, Tanuj Khattar, Mostafa Khezri, Mária Kieferová, S. Kim, Alexei Kitaev, P. V. Klimov, A. R. Klots, A. N. Korotkov, F. Kostritsa, John Mark Kreikebaum, David Landhuis, Pavel Laptev, K.-M. Lau, Lily Laws, J. Lee, Kenny Lee, Y. D. Lensky, B. J. Lester, Alexander T. Lill, W. Liu, Aditya Locharla, Orion Martin, Jarrod R. McClean, Matt McEwen, Kevin C. Miao, A. Mieszala
Abstract
Abstract Measurement has a special role in quantum theory 1 : by collapsing the wavefunction, it can enable phenomena such as teleportation 2 and thereby alter the ‘arrow of time’ that constrains unitary evolution. When integrated in many-body dynamics, measurements can lead to emergent patterns of quantum information in space–time 3–10 that go beyond the established paradigms for characterizing phases, either in or out of equilibrium 11–13 . For present-day noisy intermediate-scale quantum (NISQ) processors 14 , the experimental realization of such physics can be problematic because of hardware limitations and the stochastic nature of quantum measurement. Here we address these experimental challenges and study measurement-induced quantum information phases on up to 70 superconducting qubits. By leveraging the interchangeability of space and time, we use a duality mapping 9,15–17 to avoid mid-circuit measurement and access different manifestations of the underlying phases, from entanglement scaling 3,4 to measurement-induced teleportation 18 . We obtain finite-sized signatures of a phase transition with a decoding protocol that correlates the experimental measurement with classical simulation data. The phases display remarkably different sensitivity to noise, and we use this disparity to turn an inherent hardware limitation into a useful diagnostic. Our work demonstrates an approach to realizing measurement-induced physics at scales that are at the limits of current NISQ processors.