Non-invasive measurement of currents in analog quantum simulators

Abstract

Despite the pristine abilities of analog quantum simulators to study quantum dynamics, possibilities to detect currents are sparse. Here, we propose a flexible non-invasive technique to measure currents in quantum many-body systems by weakly coupling the system to an ancilla, followed by a measurement of the ancilla population. We numerically benchmark the scheme at the example of interacting bosons in a Harper-Hofstadter optical-lattice ladder, and discuss potential experimental error sources. The highly flexible protocol can be used with both hard-core and soft-core bosons as well as fermions, is easily extendable to more general observables like current-current correlations, and applies to other setups beyond cold atoms as we exemplify for the trapped-ion platform.

5+11 pages, 2+2 figures

References in corpus (9)

• Single-Atom Resolved Fluorescence Imaging of an Atomic Mott Insulator
• Multi-Component Quantum Gases in Spin-Dependent Hexagonal Lattices
• Observation of Quantized Conductance in Neutral Matter
• Efficient ground-state cooling of large trapped-ion chains with an EIT tripod scheme
• Artificial gauge fields with ultracold atoms
• Vortex lattices of bosons in deep rotating optical lattices
• Quantum disorder in the spatially completely anisotropic triangular lattice I: Heisenberg $S=1/2$ antiferromagnet
• Quantum disorder in the spatially completely anisotropic triangular lattice II: frustrated hard-core bosons
• Optimal scaling of persistent currents for interacting bosons on a ring