TY  - JOUR
A1  - Fumani, F. Khastehdel
A1  - Nemati, Somayyeh
A1  - Mahdavifar, Saeed
T1  - Quantum critical lines in the ground state phase diagram of spin-1/2 frustrated transverse-field ising chains
JF  - Annalen der Physik
N2  - This paper focuses on the ground state phase diagram of a 1D spin-1/2 quantum Ising model with competing first and second nearest neighbour interactions known as the axial next nearest neighbour Ising model in the presence of a transverse magnetic field. Here, using quantum correlations, both numerically and analytically, some evidence is provided to clarify the identification of the ground state phase diagram. Local quantum correlations play a crucial role in detecting the critical lines either revealed or hidden by symmetry-breaking. A non-symmetry-breaking disorder transition line can be identified by the first derivative of both entanglement of formation and quantum discord between nearest neighbour spins. In addition, the quantum correlations between the second neighbour spins can also be used to reveal Kosterlitz-Thouless phase transition when their interaction strength grows and becomes closer to the first nearest neighbour one. The results obtained using the Jordan-Wigner transformation confirm the accuracy of the numerical case.
KW  - axial next nearest neighbour Ising chains
KW  - quantum correlations
KW  - quantum
KW  - phase transitions
Y1  - 2020
U6  - https://doi.org/10.1002/andp.202000384
SN  - 0003-3804
SN  - 1521-3889
VL  - 533
IS  - 2
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Sorgenfrei, Nomi
A1  - Giangrisostomi, Erika
A1  - Jay, Raphael Martin
A1  - Kühn, Danilo
A1  - Neppl, Stefan
A1  - Ovsyannikov, Ruslan
A1  - Sezen, Hikmet
A1  - Svensson, Svante
A1  - Föhlisch, Alexander
T1  - Photodriven transient picosecond top-layer semiconductor to metal phase-transition in p-doped molybdenum disulfide
JF  - Advanced materials
N2  - Visible light is shown to create a transient metallic S-Mo-S surface layer on bulk semiconducting p-doped indirect-bandgap 2H-MoS2. Optically created electron-hole pairs separate in the surface band bending region of the p-doped semiconducting crystal causing a transient accumulation of electrons in the surface region. This triggers a reversible 2H-semiconductor to 1T-metal phase-transition of the surface layer. Electron-phonon coupling of the indirect-bandgap p-doped 2H-MoS2 enables this efficient pathway even at a low density of excited electrons with a distinct optical excitation threshold and saturation behavior. This mechanism needs to be taken into consideration when describing the surface properties of illuminated p-doped 2H-MoS2. In particular, light-induced increased charge mobility and surface activation can cause and enhance the photocatalytic and photoassisted electrochemical hydrogen evolution reaction of water on 2H-MoS2. Generally, it opens up for a way to control not only the surface of p-doped 2H-MoS2 but also related dichalcogenides and layered systems. The findings are based on the sensitivity of time-resolved electron spectroscopy for chemical analysis with photon-energy-tuneable synchrotron radiation.
KW  - catalysis
KW  - dichalcogenides
KW  - hydrogen evolution reaction
KW  - phase transitions
KW  - photoelectron spectroscopy
Y1  - 2021
U6  - https://doi.org/10.1002/adma.202006957
SN  - 0935-9648
SN  - 1521-4095
VL  - 33
IS  - 14
PB  - Wiley-VCH
CY  - Weinheim
ER  -