Methods, systems, and devices for wireless communications are described. A user equipment (UE) may transmit, to a base station, a control message indicating a capability of the UE to operate in a full duplex mode on a single carrier in an unpaired radio frequency spectrum. The UE may receive, from the base station, control signaling indicating a default bandwidth part associated with the full duplex mode or a half-duplex mode based at least in part on the control message. The UE and the base station may communicate using an active bandwidth part. The UE and the base station may then communicate, based on an expiration of an inactivity timer associated with the active bandwidth part, using the default bandwidth part in accordance with the full duplex mode/or the half-duplex mode.