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arXiv · 2206.05254

Formation of robust bound states of interacting microwave photons

Alexis Morvan·Trond I. Andersen·Xiao Mi·Charles Neill·Andre Petukhov·Kostyantyn Kechedzhi·Dmitry Abanin·Rajeev Acharya·Frank Arute·Kunal Arya·Abraham Asfaw·Juan Atalaya·Ryan Babbush·Dave Bacon·Joseph C. Bardin·Joao Basso·Andreas Bengtsson·Gina Bortoli·Alexandre Bourassa·Jenna Bovaird·Leon Brill·Michael Broughton·Bob B. Buckley·David A. Buell·Tim Burger·Brian Burkett·Nicholas Bushnell·Zijun Chen·Ben Chiaro·Roberto Collins·Paul Conner·William Courtney·Alexander L. Crook·Ben Curtin·Dripto M. Debroy·Alexander Del Toro Barba·Sean Demura·Andrew Dunsworth·Daniel Eppens·Catherine Erickson·Lara Faoro·Edward Farhi·Reza Fatemi·Leslie Flores Burgos·Ebrahim Forati·Austin G. Fowler·Brooks Foxen·William Giang·Craig Gidney·Dar Gilboa·Marissa Giustina·Alejandro Grajales Dau·Jonathan A. Gross·Steve Habegger·Michael C. Hamilton·Matthew P. Harrigan·Sean D. Harrington·Jeremy Hilton·Markus Hoffmann·Sabrina Hong·Trent Huang·Ashley Huff·William J. Huggins·Sergei V. Isakov·Justin Iveland·Evan Jeffrey·Zhang Jiang·Cody Jones·Pavol Juhas·Dvir Kafri·Tanuj Khattar·Mostafa Khezri·Marika Kieferova·Seon Kim·Alexei Kitaev·Paul V. Klimov·Andrey R. Klots·Alexander N. Korotkov·Fedor Kostritsa·John Mark Kreikebaum·David Landhuis·Pavel Laptev·Kim-Ming Lau·Lily Laws·Joonho Lee·Kenny Lee·Brian J. Lester·Alexander Lill·Wayne Liu·Aditya Locharla·Erik Lucero·Fionn D. Malone·Orion Martin·Jarrod R. McClean·Matt McEwen·Bernardo Meurer Costa·Kevin C. Miao·Masoud Mohseni·Shirin Montazeri·Emily Mount

Abstract

Systems of correlated particles appear in many fields of science and represent some of the most intractable puzzles in nature. The computational challenge in these systems arises when interactions become comparable to other energy scales, which makes the state of each particle depend on all other particles. The lack of general solutions for the 3-body problem and acceptable theory for strongly correlated electrons shows that our understanding of correlated systems fades when the particle number or the interaction strength increases. One of the hallmarks of interacting systems is the formation of multi-particle bound states. In a ring of 24 superconducting qubits, we develop a high fidelity parameterizable fSim gate that we use to implement the periodic quantum circuit of the spin-1/2 XXZ model, an archetypal model of interaction. By placing microwave photons in adjacent qubit sites, we study the propagation of these excitations and observe their bound nature for up to 5 photons. We devise a phase sensitive method for constructing the few-body spectrum of the bound states and extract their pseudo-charge by introducing a synthetic flux. By introducing interactions between the ring and additional qubits, we observe an unexpected resilience of the bound states to integrability breaking. This finding goes against the common wisdom that bound states in non-integrable systems are unstable when their energies overlap with the continuum spectrum. Our work provides experimental evidence for bound states of interacting photons and discovers their stability beyond the integrability limit.

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Alexis Morvan, Trond I. Andersen, Xiao Mi, Charles Neill, Andre Petukhov, Kostyantyn Kechedzhi, Dmitry Abanin, Rajeev Acharya, Frank Arute, Kunal Arya, Abraham Asfaw, Juan Atalaya, Ryan Babbush, Dave Bacon, Joseph C. Bardin, Joao Basso, Andreas Bengtsson, Gina Bortoli, Alexandre Bourassa, Jenna Bovaird, Leon Brill, Michael Broughton, Bob B. Buckley, David A. Buell, Tim Burger, Brian Burkett, Nicholas Bushnell, Zijun Chen, Ben Chiaro, Roberto Collins, Paul Conner, William Courtney, Alexander L. Crook, Ben Curtin, Dripto M. Debroy, Alexander Del Toro Barba, Sean Demura, Andrew Dunsworth, Daniel Eppens, Catherine Erickson, Lara Faoro, Edward Farhi, Reza Fatemi, Leslie Flores Burgos, Ebrahim Forati, Austin G. Fowler, Brooks Foxen, William Giang, Craig Gidney, Dar Gilboa, Marissa Giustina, Alejandro Grajales Dau, Jonathan A. Gross, Steve Habegger, Michael C. Hamilton, Matthew P. Harrigan, Sean D. Harrington, Jeremy Hilton, Markus Hoffmann, Sabrina Hong, Trent Huang, Ashley Huff, William J. Huggins, Sergei V. Isakov, Justin Iveland, Evan Jeffrey, Zhang Jiang, Cody Jones, Pavol Juhas, Dvir Kafri, Tanuj Khattar, Mostafa Khezri, Marika Kieferova, Seon Kim, Alexei Kitaev, Paul V. Klimov, Andrey R. Klots, Alexander N. Korotkov, Fedor Kostritsa, John Mark Kreikebaum, David Landhuis, Pavel Laptev, Kim-Ming Lau, Lily Laws, Joonho Lee, Kenny Lee, Brian J. Lester, Alexander Lill, Wayne Liu, Aditya Locharla, Erik Lucero, Fionn D. Malone, Orion Martin, Jarrod R. McClean, Matt McEwen, Bernardo Meurer Costa, Kevin C. Miao, Masoud Mohseni, Shirin Montazeri, Emily Mount. 2022-06-10. Formation of robust bound states of interacting microwave photons. https://doi.org/10.1038/s41586-022-05348-y

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