Journal Article polymorphism van der Waals heterostructures Review giant Stark effect phase transitions 1D edge contacts 2D ferroelectricity 2D materials CrI3 Lifshitz transition alloys angle‐resolved photoemission spectroscopy anomalous Hall conductivity atomically thin materials charge density waves charge transfer contact resistance correlated states ferromagnetism germanium selenide grain boundary free hole carriers in Cu in-memory computing lateral heterostructures layered semimetals low dimensional materials magnetized graphene memtransistor memtransistors