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Your search keyword '"Pai, Woei Wu"' showing total 8 results
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8 results on '"Pai, Woei Wu"'

1. Zero-point entropies of spin-jam and spin-glass states in a frustrated magnet

Author

Piyakulworawat, Chairote, Thennakoon, Asiri, Yang, Junjie, Yoshizawa, Hideki, Ueta, Daichi, Sato, Taku J, Sheng, Kuan, Chen, Wei-Tin, Pai, Woei-Wu, Matan, Kittiwit, and Lee, Seung-Hun

Subjects
Condensed Matter - Strongly Correlated Electrons, Condensed Matter - Disordered Systems and Neural Networks
Abstract

Thermodynamics studies of a prototypical quasi-two-dimensional frustrated magnet Ba$_2$Sn$_2$ZnCr$_{7p}$Ga$_{10-7p}$O$_{22}$ where the magnetic Cr$^{3+}$ ions are arranged in a triangular network of bipyramids show that the magnetic zero-point entropy for $p=0.98$ is 55(1)\% of the entropy expected when the Cr$^{3+}$ moments are fully disordered. Furthermore, when combined with a previous neutron scattering study and the perimeter scaling entropy of a spin jam, the analysis reveals that with decreasing $p$, i.e., doping of the nonmagnetic Ga$^{3+}$ ions, the variation in the magnetic zero-point entropy can be well explained by the combined effects of the zero-point entropy of the spin jam state and that of weakly coupled orphan spins, shedding light on the coexistence of the two types of spin states in quantum magnetism., Comment: 8 pages, 4 figures, and Supplemental Material

Published
2023
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2. Formation of Monolayer Charge Density Waves and Anomalous Edge Doping in Na Doped Bulk VSe2

Author

Chazarin, Ulysse, primary, Lezoualc'h, Mahé, additional, Chou, Jyh‐Ping, additional, Pai, Woei Wu, additional, Karn, Abhishek, additional, Sankar, Raman, additional, Chacon, Cyril C., additional, Girard, Yann, additional, Repain, Vincent, additional, Bellec, Amandine, additional, Rousset, Sylvie, additional, Smogunov, Alexander, additional, Dappe, Yannick J., additional, and Lagoute, Jérôme, additional

Published
2022
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3. Identification and Manipulation of Defects in Black Phosphorus

Author

Harsh, Rishav, primary, Mondal, Sourav, additional, Sharma, Devina, additional, Bouatou, Mehdi, additional, Chacon, Cyril, additional, Ilyn, Maxim, additional, Rogero, Celia, additional, Repain, Vincent, additional, Bellec, Amandine, additional, Girard, Yann, additional, Rousset, Sylvie, additional, Sankar, Raman, additional, Pai, Woei Wu, additional, Narasimhan, Shobhana, additional, and Lagoute, Jérôme, additional

Published
2022
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4. Supporting Information - Identification and Manipulation of Defects in Black Phosphorus

Author

Harsh, Rishav, Mondal, Sourav, Sharma, Devina, Bouatou, Mehdi, Chacon, Cyril, Ilyn, Max, Rogero, Celia, Repain, V., Bellec, Amandine, Girard, Yann, Rousset, S., Sankar, Raman, Pai, Woei Wu, Narasimhan, Shobhana, Lagoute, Jérôme, Harsh, Rishav, Mondal, Sourav, Sharma, Devina, Bouatou, Mehdi, Chacon, Cyril, Ilyn, Max, Rogero, Celia, Repain, V., Bellec, Amandine, Girard, Yann, Rousset, S., Sankar, Raman, Pai, Woei Wu, Narasimhan, Shobhana, and Lagoute, Jérôme

Published
2022

5. Identification and manipulation of defects in black phosphorus

Author

Indo-French Centre for the Promotion of Advanced Research, Agence Nationale de la Recherche (France), Sheikh Saqr Laboratory (India), Board of Research in Nuclear Sciences (India), Harsh, Rishav, Mondal, Sourav, Sharma, Devina, Bouatou, Mehdi, Chacon, Cyril, Ilyn, Max, Rogero, Celia, Repain, V., Bellec, Amandine, Girard, Yann, Rousset, S., Sankar, Raman, Pai, Woei Wu, Narasimhan, Shobhana, Lagoute, Jérôme, Indo-French Centre for the Promotion of Advanced Research, Agence Nationale de la Recherche (France), Sheikh Saqr Laboratory (India), Board of Research in Nuclear Sciences (India), Harsh, Rishav, Mondal, Sourav, Sharma, Devina, Bouatou, Mehdi, Chacon, Cyril, Ilyn, Max, Rogero, Celia, Repain, V., Bellec, Amandine, Girard, Yann, Rousset, S., Sankar, Raman, Pai, Woei Wu, Narasimhan, Shobhana, and Lagoute, Jérôme

Abstract

We identify and manipulate commonly occurring defects in black phosphorus, combining scanning tunneling microscopy experiments with density functional theory calculations. A ubiquitous defect, imaged at negative bias as a bright dumbbell extending over several nanometers, is shown to arise from a substitutional Sn impurity in the second sublayer. Another frequently observed defect type is identified as arising from an interstitial Sn atom; this defect can be switched to a more stable configuration consisting of a Sn substitutional defect + P adatom, by application of an electrical pulse via the STM tip. DFT calculations show that this pulse-induced structural transition switches the system from a non-magnetic configuration to a magnetic one. We introduce States Projected Onto Individual Layers (SPOIL) quantities which provide information about atom-wise and orbital-wise contributions to bias-dependent features observed in STM images.

Published
2022

7. Modification of monolayer 1T-VSe2 by selective deposition of vanadium and tellurium.

Author

Karn, Abhishek, Chan, Yang Hao, Chazarin, Ulysse, Chen, Peng, and Pai, Woei Wu

Subjects
VANADIUM, CHARGE density waves, MONOMOLECULAR films, TRANSITION metals, TELLURIUM, SURFACE structure, MOLECULAR beams
Abstract

Hetero-structures of transition metal dichalcogenide (TMD) layers offer vast possibilities of new materials properties. The growth behaviors of such TMD hetero-structures can be complex. In this study, we report the structure modification of a VSe2 monolayer by the molecular beam deposition of Te, V, or both. With a typical growth temperature of 300 °C and a nominal flux rate, we found that Te deposition leaves the VSe2 intact. Vanadium deposition, in contrast, leads to small clusters ordered in stripes along well-defined directions. The charge density wave symmetry of monolayer VSe2 surprisingly changes in small regions enclosed by such vanadium stripes. With V and Te co-deposition, a dramatic change of the monolayer surface structure to a (2 × 1) ordered phase is observed. This study illustrates the unexpected complexities involved in preparing even a simple bilayer TMD hetero-structure, such as VTe2/VSe2. [ABSTRACT FROM AUTHOR]

Published
2022
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8. Spatially Extended Charge Density Wave Switching by Nanoscale Local Manipulation in a VTe2Monolayer

Author

Chazarin, Ulysse, Lezoualc’h, Mahé, Karn, Abhishek, Chou, Jyh-Ping, Pai, Woei Wu, Chacon, Cyril, Girard, Yann, Repain, Vincent, Bellec, Amandine, Rousset, Sylvie, González, César, Smogunov, Alexander, Lagoute, Jérôme, and Dappe, Yannick J.

Abstract

Monolayer transition metal dichalcogenide VTe2exhibits multiple charge density wave (CDW) phases, mainly (4 × 4) and (4 × 1). Here we report facile dynamic and tens-of-nanometer scale switching between these CDW phases with gentle bias pulses in scanning tunneling microscopy. Bias pulses purposely stimulate a reversible random CDW symmetry change between the isotropic (4 × 4) and anisotropic (4 × 1) CDWs, as well as CDW phase slips and rotation. The switching threshold of ∼1.0 V is independent of bias polarity, and the switching rate varies linearly with the tunneling current. Density functional theory calculations indicate that a coherent CDW phase switching incurs an energy barrier of ∼2.0–3.0 eV per (4 × 4) unit cell. While there is a challenge in understanding the observed large-area CDW random fluttering, we provide some possible explanations. The ability to manipulate electronic CDW phases sheds new light on tailoring CDW properties on demand.

Published
2024
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