A simple twist between two sheets of carbon crystals has taken the condensed-matter-physics community by storm. The discovery of superconductivity and other phenomena in MATBG, announced in 2018, has revealed an array of new options to also realize interacting topology, magnetism, and other many-body states of matter, in an entirely novel and simple way. Now, seven years after that initial revelation, researchers are still trying to grasp the full details of its complex phase diagram. In this talk I will give an overview of my group’s efforts in the study of MATBG devices in the recent years [1,2] and point towards its challenges and opportunities. In particular, I will discuss a cumulative phase diagram that we were able to assemble by in detail studying more than 54 MATBG devices [3]. I will discuss recent improvements in fabrication protocols of MATBG [4], and a possible route to improve it even further using QTM [5]. Last but not least I will show that the dilute superconducting state of MATBG can be used for ultra-sensitive detection of single photons [6].
–
Publication: [1] Twisted bilayer graphene's gallery of phases, B.A. Bernevig and D.K. Efetov, Physics Today 77 (4), 38–44 (2024).<br><br>[2] B.A. Bernevig, A. MacDonald, D. Xiao, X. Xu and D.K. Efetov, Review of Moden Physics - in preparation.<br><br>[3] High-yield fabrication of bubble-free magic-angle twisted bilayer graphene devices with high twist-angle homogeneity, J. Diez-Merida, I. Das, G. Di Battista, A. Diez-Carlon, M. Lee, L. Zeng, K. Watanabe, T. Taniguchi, E. Olsson, D.K. Efetov, Newton – in press (arXiv:2405.11323).<br><br>[4] In preparation.<br><br>[5] In preparation. <br><br>[6] Infrared single-photon detection with superconducting magic-angle twisted bilayer graphene, G. DiBattista, K.C. Fong, A. Diez-Carlon, K. Watanabe, T. Taniguchi, D.K. Efetov, Science Advances, 10, 8 (2024).
