Squeezing the best out of 2D materials
일 시 : 2021년 04월 06일 화요일 16:00
연 사 : 김 영 욱 교수 (DGIST)
장 소 : 온라인 진행 ( https://us02web.zoom.us/j/89235295426 , 줌회의 ID: 892 3529 5426 )
HOST : 천 상 모 교수님
초 록
Strong The study of two dimensional electron systems with extraordinarily low levels of disorder was for a long time the exclusive privilege of the epitaxial thin film research community. The successful isolation of graphene by mechanical exfoliation has, however, been truly disruptive. Furthermore, the assembly of heterostructures consisting of several layers of different 2D materials in arbitrary order by exploiting van der Waals forces has been a game changer in the field of low dimensional physics. It can be generalized to the large class of strictly 2D materials and offers unprecedented parameters to play with in order to tune electronic and other properties. It has led to a paradigm shift in the field of 2D condensed matter physics with bright prospects.
I will introduce state-of-the-art fabrication technique for building van der Waals heterostructure and show decent quantum Hall states in high quality graphene based heterostructures that show novel even denominator fractional quantum Hall states in bilayer graphene [1] and monolayer graphene [2], and also layer coherence mode in 2 degree twisted bilayer graphene. [3] In addition, I will show low temperature electronic transport study of van der Waals heterostructures composed of a single graphene layer proximitized with α-RuCl3.[4] An unexpected damping of the quantum oscillations as well as a zero-field resistance upturn close to the Néel temperature of α-RuCl3 suggest the onset of additional spin scattering due to spin fluctuations in the α-RuCl3. This approach can unlock a-RuCl3 hidden quantum states in low temperature through electrical transport.