Toward Analog Quantum Simulation of Kondo Lattice Models Using Hybrid Metal–Semiconductor Quantum Dots

InAs quantum wells have recently enabled the design of hybrid metal–semiconductor quantum dots with tunable transmission of quantum Hall edge modes [1] and large charging energies [2], providing a platform for probing quantum criticality over extended energy scales with high tunabilities. Building on this foundation, we demonstrate another key building block for such hybrid architectures: a near-unity transmission of quantum Hall edge modes into a submicron metallic island. This reflectionless coupling allows the metallic island to grant the hybrid quantum dot a continuum of single-particle states. Using an annealed Pd/Ge island material, we measured edge-mode transmission on ν = 2, 3, and 4 quantum Hall plateaus averaging above 98% across multiple devices. We also performed charge noise spectroscopy and cross-sectional TEM to evaluate the electrostatic environment around the metallic island and the nature of the metal–semiconductor interface.