[f(k)] Kollokvio perjantaina 15.9. // Peter Liljeroth: Realizing designer quantum materials with van der Waals heterostructures

[Viestintävastaava Fyysikkokerho]

Heippahei,

syksyn ensimmäinen kollokvio on täällä!

Kollokvio pidetään tämän viikon perjantaina 15.9. klo 10 luentosalissa 
FYS1. Puhujana tässä kollokviossa on Peter Liljeroth Aalto-yliopistosta 
ja aiheena on "Realizing designer quantum materials with van der Waals 
heterostructures". Kaikentasoiset kuuntelijat ovat tervetulleita 
kollokvioihin ja tämä on otettu huomioon esityksiä tehdessä. Kollokvion 
alussa on kahvitarjoilu ja koko kesto on noin tunti. Tervetuloa 
kuuntelemaan!

Alla vielä alkuperäinen kollokviokutsu.

Ystävällisin terveisin,
Mirva Toivio
Viestintävastaava
Jyväskylän Fyysikkokerho ry

--------------------------------------


Welcome to the University of Jyväskylä physics colloquium.

On Friday 15th September at 10 am in FYS1 and Zoom [1] (passcode
890524):

Peter Liljeroth, Aalto University:

Realizing designer quantum materials with van der Waals heterostructures
Conventional materials hosting exotic quantum phases typically have
complex atomic structures, inhomogeneities from defects, impurities, and
dopants making it difficult to rationally engineer their electronic
properties. This can be overcome using van der Waals (vdW)
heterostructures that allow an almost arbitrary selection of the
heterostructure building blocks, including metals and insulators,
charge-density wave systems, superconductors, magnets, correlated
insulators, and ferroelectrics. In a vdW heterostructure, the layers
interact only through vdW forces and can keep their intrinsic
properties. However, proximity effects cause properties to “leak”
between the adjacent layers and allow creating exotic quantum mechanical
phases that arise from the interactions between the layers. These key
features have recently made it possible to realize exotic quantum phases
by design and engineer responses that do not occur in natural materials.

I will highlight these concepts through our results on realizing
topological superconductivity and heavy-fermion physics in vdW
heterostructures [1-3]. Topological superconductivity requires combining
superconductivity with Rashba-type spin-orbit interactions and
magnetism. This can be realized by combining monolayer ferromagnet CrBr3
with superconducting NbSe2 [1,2]. On the other hand, the building blocks
of heavy fermion systems - Kondo coupling between a lattice of localized
magnetic moments and mobile conduction electrons - can be mimicked in
1T/1H-TaS2 heterostructures [3]. Depending on the relative strengths of
the coupling between the localized moments and the Kondo coupling, the
system can be either in a magnetic ground state or in the heavy fermion
regime. Exploring the phase diagram of these two phases offers a
promising route towards unconventional superconductivity [4]. In
general, these examples highlight the versatility of vdW
heterostructures in realizing quantum states that are difficult to find
and control in naturally occurring materials.

[1] S. Kezilebieke, M.N. Huda, V. Vaňo, M. Aapro, S.C. Ganguli, O.J.
Silveira, S. Głodzik, A.S. Foster, T. Ojanen, P. Liljeroth, Nature 588
(2020) 424.
[2] S. Kezilebieke, V. Vaňo, M.N. Huda, M. Aapro, S.C. Ganguli, P.
Liljeroth, J.L. Lado, Nano Lett. 22 (2022) 328.
[3] V. Vaňo, M. Amini, S.C. Ganguli, G. Chen, J.L. Lado, S.
Kezilebieke, P. Liljeroth, Nature 599, (2021) 582.
[4] S. Wirth, F. Steglich, Nat. Rev. Mater. 1 (2016) 16051.
Welcome!

Coffee will be served in the lobby. Although on-site attendance is the
preferred option, you can also join via Zoom. Please do not send chat
messages in Zoom during the talk, except if you need to tell about a
muted speaker.

Confirmed colloquium talks in the Fall 2023:
6.10. Danny Porath (Jerusalem): _Molecular electronics with DNA towards
detection of nucleic acids_ (tentative)
27.10. Päivi Törmä (Aalto): _Room temperature superconductivity by
2033 _(tentative)
3.11. Mathias Kläui (Mainz): _Spintronics today _(tentative)
10.11. Andreas Norman (UEF): _Quantum complementarities in vectorial
light fields_

There are still a few open slots for the fall. Suggestions for other
colloquium talks are welcome.

Tero & Iain

-- 
Tero Heikkilä
Professor, Department of Physics
University of Jyväskylä


Links:
------
[1] https://jyufi.zoom.us/j/66703175507