Exploring quantum matter with Raman spectroscopy under extreme conditions
일 시 : 2024년 11월 25일 월요일 16:30
연 사 : Dirk Wulferding 박사 (IBS Center)
장 소 : 자연과학관 B119호
초 록
Quantum spin liquids are highly correlated states of matter that evade conventional ordering processes and thereby lack any classical order parameter. Their ground state is characterized by emerging long-range entangled quasiparticles that may obey unconventional quantum statistics. Such states can be realized in low-dimensional spin systems with triangular motifs, such as a kagome lattice. However, oftentimes real materials settle into conventional magnetic order for T -> 0 stabilized by additional magnetic exchange interaction terms or due to slight lattice distortions that partially relieve the magnetic frustration. The resulting subtle imbalance between competing magnetic exchange paths can give rise to an interesting interplay between different kinds of coexisting magnetic excitations - e.g., unconventional spinons vs. conventional magnons. Furthermore, applying magnetic fields can unveil intricate dynamics between different phases [1,2].
In this talk I will review how we can employ Raman spectroscopy to identify these different kinds of quasiparticles and their underlying states [3], and I will compare recent results on several related Cu-based s=1/2 networks with different degrees of frustration.
[1] Jeon, et al., Nat. Phys. 20, 435 (2024).
[2] Wulferding, et al., Nat. Commun. 11, 1603(2020).
[3] Wulferding, et al., J. Phys.: Condens. Matter 32, 043001 (2020).