Observation of emergent Z2 gauge invariance in a superconducting circuit
Zhan Wang, Zi-Yong Ge, Zhongcheng Xiang +8 more
Lattice gauge theories (LGTs) are one of the most fundamental subjects in many-body physics, and has recently attracted considerable research interests in quantum simulations.Here we experimentally investigate the emergent Z 2 gauge invariance in a 1D superconducting circuit with 10 transmon qubits.By precisely adjusting staggered longitudinal and transverse fields to each qubit, we construct an effective Hamiltonian containing anLGT and gauge-broken terms.The corresponding matter sector can exhibit a localization, and there also exists a 3-qubit operator, of which the expectation value can retain nonzero for a long time in low-energy regimes.The above localization can be regarded as the confinement of matter fields, and the 3-body operator is the Z 2 gauge generator.These experimental results demonstrate that, despite the absence of gauge structure in the effective Hamiltonian, Z 2 gauge invariance can still emerge in low-energy regimes.Our work provides a method for both theoretically and experimentally studying the rich physics in quantum many-body systems with emergent gauge invariance.
arXiv:2111.05048•Physical Review Research•Jun 17, 2022•37 citations