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Special ICMT Seminar: Novel Electronics of Honeycomb Charge-Density Wave Networks

Event Type
Seminar/Symposium
Sponsor
The Institute for Condensed Matter Theory
Location
190 ESB
Date
Oct 23, 2019   10:00 am  
Speaker
Gil Young Cho,
Views
41
Originating Calendar
Physics - The Anthony J Leggett Institute for Condensed Matter Theory Seminar

We uncover a rich phenomenology of the self-organized honeycomb network superstructure of one-dimensional metals, which may play a significant role in understanding global phase diagram topology and emerging superconductivity of charge-density wave materials such as 1T-TaS${}_2$. One of the most important problems about these materials and theoretical condensed matter physics is the origin of superconductivity inside this seemingly competing nearly-commensurate charge-density wave state. The key observation is that the honeycomb network emeging in the charge-density wave state magically supports a cascade of flat bands, whose unusual stability we thoroughly investigate. Furthermore, by combining the weak-coupling mean-field and strong-coupling approaches, we argue that the superconductivity will be strongly enhanced in the network. This provides a natural mechanism for emerging superconductivity from the network superstructure, and this explains the phase diagram topology of these charge density wave materials. Not only explaining emerging superconductivity, we show that abundant topological states including the corner states, which are closely related to that of the higher-order topology, appear. The results reported here can be generically applicable to various other systems with similar network superstructures.

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