arXiv:2306.09333
Dynamics of magnetization at infinite temperature in a Heisenberg spin chain
Eliott N. Rosenberg, Trond I. Andersen, Rhine Samajdar, A. G. Petukhov, Jesse C. Hoke, Dmitry A. Abanin, Andreas Bengtsson, Ilya Drozdov, Catherine Erickson, Paul V. Klimov, Xiao Mi, Alexis Morvan, M. Neeley, C. Neill, Rajeev Acharya, Allen, Richard, Anderson, Kyle, M. Ansmann, Frank Arute, Kunal Arya, Abraham T. Asfaw, Juan Atalaya, Joseph C. Bardin, Alexander Bilmes, Gina Bortoli, Alexandre Bourassa, Jenna Bovaird, L. Brill, Michael Broughton, Bob B. Buckley, David A. Buell, Tim Burger, Brian Burkett, Nicholas Bushnell, Juan Campero, Hung-Shen Chang, Zijun Chen, Benjamin Chiaro, Desmond Chik, J. G. Cogan, Roberto Collins, Paul W. Conner, William Courtney, Alexander L. Crook, Ben Curtin, Dripto M. Debroy, Alexander Del Toro Barba, Sean Demura, Agustín Di Paolo, Andrew Dunsworth, Clint Earle, Edward Farhi, Reza Fatemi, Vinicius Ferreira, Leslie Flores, Ebrahim Forati, Austin G. Fowler, Brooks Foxen, Garcia, Gonzalo, Élie Genois, William Giang, Craig Gidney, Dar Gilboa, Marissa Giustina, Raja Gosula, Alejandro Grajales Dau, Jonathan A. Gross, Steve Habegger, Hamilton, Michael, Monica A. Hansen, Matthew P. Harrigan, Sean David Harrington, Paula Heu, Hill, Gordon, Hoffmann, Markus, Sabrina Hong, Trent Huang, Ashley Huff, William J. Huggins, L. B. Ioffe, Sergei V. Isakov, Justin Iveland, Evan R. Jeffrey, Jiang Zhang, Cody Jones, Pavol Juhás, Dvir Kafri, Tanuj Khattar, Mostafa Khezri, Mária Kieferová, Seon Kim, Alexei Kitaev, A. R. Klots, Alexander N. Korotkov, Fedor Kostritsa, John Mark Kreikebaum, David Landhuis, Pavel Laptev, Kim Ming Lau, Lily Laws
Abstract
Understanding universal aspects of quantum dynamics is an unresolved problem in statistical mechanics. In particular, the spin dynamics of the 1D Heisenberg model were conjectured to belong to the Kardar-Parisi-Zhang (KPZ) universality class based on the scaling of the infinite-temperature spin-spin correlation function. In a chain of 46 superconducting qubits, we study the probability distribution, $P(\mathcal{M})$, of the magnetization transferred across the chain's center. The first two moments of $P(\mathcal{M})$ show superdiffusive behavior, a hallmark of KPZ universality. However, the third and fourth moments rule out the KPZ conjecture and allow for evaluating other theories. Our results highlight the importance of studying higher moments in determining dynamic universality classes and provide key insights into universal behavior in quantum systems.