Observation of 2D quantum Griffiths singularity and potential topological superconductivity
Physics Colloquium
3:30 pm –
5:00 pm
Jorgensen Hall Room: 136
Speaker: Jian Wang, Peking University
Host: Xia Hong
By both in situ scanning tunneling microscopy/spectroscopy and ex situ transport and magnetization measurements, we find that the two-atomic-layer Ga film with graphene-like structure on wide band-gap semiconductor GaN is superconducting with Tc up to 5.4 K. [1] Furthermore, in three-atomic-layer Ga films, we firstly observe quantum Griffiths singularity in two dimensional (2D) system and superconductors.[2] As for the superconductivity in topological materials, we detect the novel superconductivity in crystalline 3D Dirac semimetal Cd3As2 [3] by using point contact measurements with some signatures showing the possibility of topological superconductivity.[4]
Sketch of the B-T phase diagram of 2D SMT with quenched disorder.
References:
1. Physical Review Letters 114, 107003 (2015) (Editors’ Suggestion)
2. Science 350, 542 (2015) (with a perspective article: Science 350, 509)
3. Physical Review X 5, 031037 (2015)
4. Nature Materials 15, 38 (2016)
Host: Xia Hong
By both in situ scanning tunneling microscopy/spectroscopy and ex situ transport and magnetization measurements, we find that the two-atomic-layer Ga film with graphene-like structure on wide band-gap semiconductor GaN is superconducting with Tc up to 5.4 K. [1] Furthermore, in three-atomic-layer Ga films, we firstly observe quantum Griffiths singularity in two dimensional (2D) system and superconductors.[2] As for the superconductivity in topological materials, we detect the novel superconductivity in crystalline 3D Dirac semimetal Cd3As2 [3] by using point contact measurements with some signatures showing the possibility of topological superconductivity.[4]
Sketch of the B-T phase diagram of 2D SMT with quenched disorder.
References:
1. Physical Review Letters 114, 107003 (2015) (Editors’ Suggestion)
2. Science 350, 542 (2015) (with a perspective article: Science 350, 509)
3. Physical Review X 5, 031037 (2015)
4. Nature Materials 15, 38 (2016)