Conductivity of edge states in 1T-TaS2
ORAL
Abstract
The layered compound TaS2 has been shown to form a commensurate Charge-Density Wave (CCDW) lattice at low temperatures, and undergoes multiple fascinating transitions between nearly-commensurate and incommensurate CDW phases with increasing temperature. Such phases exhibit unique conductive properties that offer a new platform for next-generation electronic devices, namely the ultra-fast insulator-metal transition observed in CCDW 1T-TaS2 under optical or electric excitation.
Prior work in our group has shown, using a cross-bar device, that one can toggle the resistivity of CCDW-phase TaS2 via directional write currents. While initially thought to be a slidetronic effect driven by the interlayer alignment of CCDWs, state-of-the-art SQUID measurements of spatially-resolved current density show the current path to orient along lateral edges of the device. Using first principles calculations, we model the lateral edge states of 1T-TaS2 using a tight-binding approach and demonstrate the formation of mid-gap states that mediate the flow of current along the boundary. This investigation explores the topological properties of the boundary states, and surveys their sensitivity to stacking and atomic termination.
Prior work in our group has shown, using a cross-bar device, that one can toggle the resistivity of CCDW-phase TaS2 via directional write currents. While initially thought to be a slidetronic effect driven by the interlayer alignment of CCDWs, state-of-the-art SQUID measurements of spatially-resolved current density show the current path to orient along lateral edges of the device. Using first principles calculations, we model the lateral edge states of 1T-TaS2 using a tight-binding approach and demonstrate the formation of mid-gap states that mediate the flow of current along the boundary. This investigation explores the topological properties of the boundary states, and surveys their sensitivity to stacking and atomic termination.
* Funded through the NPQC (Novel Pathways to Quantum Coherence) center of the EFRC.
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Publication: Maniv, Metastable Slidetronic Switching in Bulk 1T-TaS2 (pre-print)
Presenters
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Jonathan T Reichanadter
Lawrence Berkeley National Laboratory, University of California, Berkeley
Authors
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Jonathan T Reichanadter
Lawrence Berkeley National Laboratory, University of California, Berkeley
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Jeffrey B Neaton
Lawrence Berkeley National Laboratory and UC-Berkeley
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James G Analytis
University of California, Berkeley, University of California Berkeley
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Beena Kalisky
Bar-Ilan University