scholarly journals Strain engineering Dirac surface states in heteroepitaxial topological crystalline insulator thin films

2015 ◽  
Vol 10 (10) ◽  
pp. 849-853 ◽  
Author(s):  
Ilija Zeljkovic ◽  
Daniel Walkup ◽  
Badih A. Assaf ◽  
Kane L. Scipioni ◽  
R. Sankar ◽  
...  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Vishal Bhardwaj ◽  
Anupam Bhattacharya ◽  
Shivangi Srivastava ◽  
Vladimir V. Khovaylo ◽  
Jhuma Sannigrahi ◽  
...  

AbstractHalf-Heusler compounds exhibit a remarkable variety of emergent properties such as heavy-fermion behaviour, unconventional superconductivity and magnetism. Several of these compounds have been predicted to host topologically non-trivial electronic structures. Remarkably, recent theoretical studies have indicated the possibility to induce non-trivial topological surface states in an otherwise trivial half-Heusler system by strain engineering. Here, using magneto-transport measurements and first principles DFT-based simulations, we demonstrate topological surface states on strained [110] oriented thin films of YPdBi grown on (100) MgO. These topological surface states arise in an otherwise trivial semi-metal purely driven by strain. Furthermore, we observe the onset of superconductivity in these strained films highlighting the possibility of engineering a topological superconducting state. Our results demonstrate the critical role played by strain in engineering novel topological states in thin film systems for developing next-generation spintronic devices.


Author(s):  
Manik Goyal ◽  
Honggyu Kim ◽  
Timo Schumann ◽  
Luca Galletti ◽  
Anton A. Burkov ◽  
...  

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
S. X. M. Riberolles ◽  
T. V. Trevisan ◽  
B. Kuthanazhi ◽  
T. W. Heitmann ◽  
F. Ye ◽  
...  

AbstractKnowledge of magnetic symmetry is vital for exploiting nontrivial surface states of magnetic topological materials. EuIn2As2 is an excellent example, as it is predicted to have collinear antiferromagnetic order where the magnetic moment direction determines either a topological-crystalline-insulator phase supporting axion electrodynamics or a higher-order-topological-insulator phase with chiral hinge states. Here, we use neutron diffraction, symmetry analysis, and density functional theory results to demonstrate that EuIn2As2 actually exhibits low-symmetry helical antiferromagnetic order which makes it a stoichiometric magnetic topological-crystalline axion insulator protected by the combination of a 180∘ rotation and time-reversal symmetries: $${C}_{2}\times {\mathcal{T}}={2}^{\prime}$$ C 2 × T = 2 ′ . Surfaces protected by $${2}^{\prime}$$ 2 ′ are expected to have an exotic gapless Dirac cone which is unpinned to specific crystal momenta. All other surfaces have gapped Dirac cones and exhibit half-integer quantum anomalous Hall conductivity. We predict that the direction of a modest applied magnetic field of μ0H ≈ 1 to 2 T can tune between gapless and gapped surface states.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shama ◽  
R. K. Gopal ◽  
Goutam Sheet ◽  
Yogesh Singh

AbstractPd$$_{3}$$ 3 Bi$$_{2}$$ 2 S$$_{2}$$ 2 (PBS) is a recently proposed topological semimetal candidate. However, evidence for topological surface states have not yet been revealed in transport measurements due to the large mobility of bulk carriers. We report the growth and magneto-transport studies of PBS thin films where the mobility of the bulk carriers is reduced by two orders of magnitude, revealing for the first time, contributions from the 2-dimensional (2D) topological surface states in the observation of the 2D weak anti-localization (WAL) effect in magnetic field and angle dependent conductivity measurements. The magnetotransport data is analysed within the 2D Hikami-Larkin-Nagaoka (HLN) theory. The analysis suggests that multiple conduction channels contribute to the transport. It is also found that the temperature dependence of the dephasing length can’t be explained only by electron-electron scattering and that electron-phonon scattering also contributes to the phase relaxation mechanism in PBS films.


1972 ◽  
Vol 28 (19) ◽  
pp. 1264-1268 ◽  
Author(s):  
Gerald P. Alldredge ◽  
Leonard Kleinman
Keyword(s):  

2008 ◽  
Vol 92 (16) ◽  
pp. 163102 ◽  
Author(s):  
Cheng-Maw Cheng ◽  
Ku-Ding Tsuei ◽  
Chi-Ting Tsai ◽  
Dah-An Luh

2022 ◽  
Vol 105 (3) ◽  
Author(s):  
Liesbeth Mulder ◽  
Carolien Castenmiller ◽  
Femke J. Witmans ◽  
Steef Smit ◽  
Mark S. Golden ◽  
...  

2021 ◽  
Author(s):  
Ningning Wang ◽  
Mingwei Yang ◽  
Keyu Chen ◽  
Zhen Yang ◽  
Hua Zhang ◽  
...  

Abstract The successful synthesis of superconducting nickelate thin films with the highest Tc ~ 15 K has reignited great enthusiasms on this class of potential analogue to high-Tc cuprates suggested decades ago. To pursue higher Tc is always an important task in studying new superconductors. Here we report for the first time the effect of pressure on the superconducting properties of infinite-layer Pr0.82Sr0.18NiO2 thin films by measuring electrical resistivity under various pressures in a cubic anvil cell apparatus. We find that the onset of superconductivity, Tconset, can be enhanced monotonically from ~ 18 K at ambient pressure to ~ 31 K without showing signatures of saturation upon increasing pressure to 12.1 GPa in the presence of liquid pressure transmitting medium. This encouraging result indicates that the Tc of infinite-layer nickelates superconductors can be further raised up by applying higher pressures or strain engineering in the heterostructure films. In addition to the pressure effect, we also discussed the influence of stress/strain on the superconducting properties of the nickelate thin films.


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