Strain engineering and one-dimensional organization of metal- nsulator domains in single-crystal vanadium dioxide beams

摘要

Correlated electron materials can undergo a variety of phasetransitions, including superconductivity, the metal-insulatortransition and colossal magnetoresistancel. Moreover, multiplephysical phases or domains with dimensions of nanometres tomicrometres can coexist in these materials at temperatureswhere a pure phase is expected2. Making use of the propertiesof correlated electron materials in device applications willrequire the ability to control domain structures and phase tran-sitions in these materials. Lattice strain has been shown tocause the coexistence of metallic and insulating phases in theMott insulator V02. Here, we show that we can nucleate andmanipulate ordered arrays of metallic and insulating domainsalong single-crystal beams of V02 by continuously tuning thestrain over a wide range of values. The Mott transitionbetween a low-temperature insulating phase and a high-temp-erature metallic phase usually occurs at 341 K in V02, but theactive control of strain allows us to reduce this transition temp-erature to room temperature. In addition to device applications,the ability to control the phase structure of V02 with straincould lead to a deeper understanding of the correlated electronmaterials in general.