Dust and Gas Transport in Substructured Nonideal MHD Wind-Launching Disks with Embedded Planets

Abstract

Radial dust transport in protoplanetary disks is a key process shaping planet formation and disk chemistry. We investigate how this transport, along with gas transport, is regulated in wind-launching disks with embedded planets using three-dimensional nonideal MHD simulations. We find that disk substructures do not act as absolute barriers to transport. Low-mass planets leave the disk structure dominated by the magnetic wind, while a Jupiter-mass planet opens a deep gap and drives spiral shocks. However, even in this regime, wind-driven accretion persists; the planet reshapes rather than replaces the magnetically driven flow, leaving the gap intrinsically time-dependent and partially permeable. Early-phase suppression of inward transport is followed by the development of localized, azimuthally intermittent inflow channels that enable continued cross-gap transport. This transport is strongly size-dependent: small grains remain coupled to the gas and readily penetrate the gap, whereas larger grains are efficiently trapped outside the planet. Consequently, a giant planet acts as an efficient but incomplete filter rather than a perfect barrier. These results support a "leaky gap" scenario, where radial transport is regulated rather than halted by substructures. Volatile-rich material can be delivered to the inner disk both before gap opening and via continued leakage, providing a natural explanation for the diverse inner disk compositions inferred from JWST. Similarly, pebble isolation during core growth should be viewed as a gradual filtering process rather than a binary transition. More generally, disk substructures are dynamically evolving features whose transport efficiency depends on their physical origin (magnetic versus planet-driven).