Latest Papers in Condensed Matter Physics

Mesoscale And Nanoscale Physics

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Evidence of Majorana Zero Modes in Josephson Trijunctions (1904.02677v1)

Guang Yang, Zhaozheng Lyu, Junhua Wang, Jianghua Ying, Xiang Zhang, Jie Shen, Guangtong Liu, Jie Fan, Zhongqing Ji, Xiunian Jing, Fanming Qu, Li Lu

2019-04-04

In search of fault-tolerant topological quantum computation (TQC), zero-bias conductance peak as a necessary signature of Majorana zero modes (MZMs) has been observed in a number of solid-state systems. Here, we present the signature of MZMs from a phase-sensitive experiment on Josephson trijunctions constructed on the surface of three-dimensional topological insulators. We observed that the minigap at the center of the trijunction is protected to close over extended regions in phase space, supporting in principle the Majorana phase diagram proposed by Fu and Kane in 2008. Our study paves the way for further braiding MZMs and exploring TQC on a scalable two-dimensional platform.

Intervalley Polaron in Atomically Thin Transition Metal Dichalcogenides (1904.02674v1)

M. M. Glazov, M. A. Semina, C. Robert, B. Urbaszek, T. Amand, X. Marie

2019-04-04

We study theoretically intervalley coupling in transition-metal dichalcogenide monolayers due to electron interaction with short-wavelength phonons. We demonstrate that this intervalley polaron coupling results in (i) a renormalization of the conduction band spin splitting and (ii) an increase of the electron effective masses. We also calculate the renormalization of the cyclotron energy and the Landau level splitting in the presence of an external magnetic field. An inter-valley magneto-phonon resonance is uncovered. Similar, but much weaker effects are also expected for the valence band holes. These results might help to resolve the discrepancy between ab initio values of the electron effective masses and the ones deduced from magneto-transport measurements.

Tensor network simulation of non-Markovian dynamics in organic polaritons (1804.04511v2)

Javier del Pino, Florian A. Y. N. Schröder, Alex W. Chin, Johannes Feist, Francisco J. Garcia-Vidal

2018-04-12

We calculate the exact many-body time dynamics of polaritonic states supported by an optical cavity filled with organic molecules. Optical, vibrational and radiative processes are treated on an equal footing employing the Time-Dependent Variational Matrix Product States algorithm. We demonstrate signatures of non-Markovian vibronic dynamics and its fingerprints in the far-field photon emission spectrum at arbitrary light-matter interaction scales, ranging from the weak to the strong coupling regimes. We analyse both the single and many-molecule cases, showing the crucial role played by the collective motion of molecular nuclei and dark states in determining the polariton dynamics and the subsequent photon emission.

Micromagnetic Theory of Curvilinear Ferromagnetic Shells (1904.02641v1)

Denis D. Sheka, Oleksandr V. Pylypovskyi, Pedro Landeros, Yuri Gaididei, Attila Kákay, Denys Makarov

2019-04-04

Here, we present a micromagnetic theory of curvilinear ferromagnets, which allows discovering novel fundamental physical effects which were amiss. In spite of the firm confidence for more than 70 years, we demonstrate that there is an intimate coupling between volume and surface magnetostatic charges. Evenmore, the physics of curvilinear systems requires existence of a new fundamental magnetostatic charge determined by local characteristics of the surface. As a stark consequence, novel physical nonlocal anisotropy and chiral effects emerge in spatially corrugated magnetic thin films. Besides these fundamental discoveries, this work reassures confidence in theoretical predictions for experimental explorations and novel devices, based on curved thin films.

Strong Electronic Correlation Originates from the Synergistic Effect of Large Moiré Cell and Strong Interlayer Coupling in Twisted Graphene Bilayer (1903.05232v2)

Xun-Wang Yan, Jing Li, Yanyun Wang, Miao Gao

2019-03-12

By using the first-principles method based on density of functional theory, we study the electronic properties of twisted bilayer graphene with some specific twist angles and interlayer spacings. With the decrease of the twist angle(the unit cell becomes larger), the energy band becomes narrower and Coulomb repulsion increases, leading to the enhancement of electronic correlation; On the other hand, as the interlayer spacing decreases and the interlayer coupling becomes stronger, the correlation becomes stronger. By tuning the interlayer coupling, we can realize the strongly correlated state with the band width less than 0.01 eV in medium-sized Moir'e cell of twisted bilayer graphene. These results demonstrate that the strength of electronic correlation in twisted bilayer graphene is closely related to two factors: the size of unit cell and the distance between layers. Consequently, a conclusion can be drawn that the strong electronic correlation in twisted bilayer graphene originates from the synergistic effect of the large size of Moir'e cell and strong interlayer coupling on its electronic structure.

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