Probing entanglement in a 2D hard-core Bose–Hubbard lattice
Amir H. Karamlou, Ilan T. Rosen, Sarah E. Muschinske, Cora N. Barrett, Agustín Di Paolo, Leon Ding, P. M. Harrington, Max Hays, Rabindra Nath Das, David Kim, Bethany M. Niedzielski, Meghan Schuldt, Kyle Serniak, Mollie E. Schwartz, Jonilyn Yoder, Simon Gustavsson, Yariv Yanay, Jeffrey A. Grover, William D. Oliver
Abstract
Abstract Entanglement and its propagation are central to understanding many physical properties of quantum systems 1–3 . Notably, within closed quantum many-body systems, entanglement is believed to yield emergent thermodynamic behaviour 4–7 . However, a universal understanding remains challenging owing to the non-integrability and computational intractability of most large-scale quantum systems. Quantum hardware platforms provide a means to study the formation and scaling of entanglement in interacting many-body systems 8–14 . Here we use a controllable 4 × 4 array of superconducting qubits to emulate a 2D hard-core Bose–Hubbard (HCBH) lattice. We generate superposition states by simultaneously driving all lattice sites and extract correlation lengths and entanglement entropy across its many-body energy spectrum. We observe volume-law entanglement scaling for states at the centre of the spectrum and a crossover to the onset of area-law scaling near its edges.