Science Advances

/Science Advances

Realization of flat band with possible nontrivial topology in electronic Kagome lattice

2018-11-16T22:36:24+00:00November 16th, 2018|Categories: Publications|Tags: |

The energy dispersion of fermions or bosons vanishes in momentum space if destructive quantum interference occurs in a frustrated Kagome lattice with only nearest-neighbor hopping. A discrete flat band (FB) without any dispersion is consequently formed, promising the emergence of fractional quantum Hall states at high temperatures. Here, we report

Published in: "Science Advances".

Extremely flat band in bilayer graphene

2018-11-09T20:36:28+00:00November 9th, 2018|Categories: Publications|Tags: |

We propose a novel mechanism of flat band formation based on the relative biasing of only one sublattice against other sublattices in a honeycomb lattice bilayer. The mechanism allows modification of the band dispersion from parabolic to “Mexican hat”–like through the formation of a flattened band. The mechanism is well

Published in: "Science Advances".

Entanglement signatures of emergent Dirac fermions: Kagome spin liquid and quantum criticality

2018-11-09T20:36:26+00:00November 9th, 2018|Categories: Publications|Tags: |

Quantum spin liquids (QSLs) are exotic phases of matter that host fractionalized excitations. It is difficult for local probes to characterize QSL, whereas quantum entanglement can serve as a powerful diagnostic tool due to its nonlocality. The kagome antiferromagnetic Heisenberg model is one of the most studied and experimentally relevant

Published in: "Science Advances".

Evidence for a quantum spin Hall phase in graphene decorated with Bi2Te3 nanoparticles

2018-11-09T20:36:21+00:00November 9th, 2018|Categories: Publications|Tags: |

Realization of the quantum spin Hall effect in graphene devices has remained an outstanding challenge dating back to the inception of the field of topological insulators. Graphene’s exceptionally weak spin-orbit coupling—stemming from carbon’s low mass—poses the primary obstacle. We experimentally and theoretically study artificially enhanced spin-orbit coupling in graphene via

Published in: "Science Advances".

Dynamic assembly of liquid crystalline graphene oxide gel fibers for ion transport

2018-11-02T18:36:23+00:00November 2nd, 2018|Categories: Publications|Tags: , |

Colloidal dispersions with liquid crystallinity hold great promise for fabricating their superstructures. As an example, when graphene oxide (GO) sheets are assembled in the liquid crystalline state, they can turn into ordered macroscopic forms of GO such as fibers via the wet spinning process. Here, we report that by reinforcing

Published in: "Science Advances".

Mass spectrometry imaging of the in situ drug release from nanocarriers

2018-11-01T02:36:30+00:00November 1st, 2018|Categories: Publications|Tags: , |

It is crucial but of a great challenge to study in vivo and in situ drug release of nanocarriers when developing a nanomaterial-based drug delivery platform. We developed a new label-free laser desorption/ionization mass spectrometry (MS) imaging strategy that enabled visualization and quantification of the in situ drug release in

Published in: "Science Advances".

Quantum interference mediated vertical molecular tunneling transistors

2018-10-12T22:36:38+00:00October 12th, 2018|Categories: Publications|Tags: , , |

Molecular transistors operating in the quantum tunneling regime represent potential electronic building blocks for future integrated circuits. However, due to their complex fabrication processes and poor stability, traditional molecular transistors can only operate stably at cryogenic temperatures. Here, through a combined experimental and theoretical investigation, we demonstrate a new design

Published in: "Science Advances".

Observation of long-range dipole-dipole interactions in hyperbolic metamaterials

2018-10-05T20:36:37+00:00October 5th, 2018|Categories: Publications|Tags: |

Dipole-dipole interactions (Vdd) between closely spaced atoms and molecules are related to real photon and virtual photon exchange between them and decrease in the near field connected with the characteristic Coulombic dipole field law. The control and modification of this marked scaling with distance have become a long-standing theme in

Published in: "Science Advances".

Tailoring emergent spin phenomena in Dirac material heterostructures

2018-09-22T02:36:57+00:00September 22nd, 2018|Categories: Publications|Tags: , |

Dirac materials such as graphene and topological insulators (TIs) are known to have unique electronic and spintronic properties. We combine graphene with TIs in van der Waals heterostructures to demonstrate the emergence of a strong proximity-induced spin-orbit coupling in graphene. By performing spin transport and precession measurements supported by ab

Published in: "Science Advances".

2D titanium carbide (MXene) for wireless communication

2018-09-22T02:36:55+00:00September 22nd, 2018|Categories: Publications|Tags: |

With the development of the Internet of Things (IoT), the demand for thin and wearable electronic devices is growing quickly. The essential part of the IoT is communication between devices, which requires radio-frequency (RF) antennas. Metals are widely used for antennas; however, their bulkiness limits the fabrication of thin, lightweight,

Published in: "Science Advances".

Programmable wettability on photocontrolled graphene film

2018-09-15T00:36:40+00:00September 15th, 2018|Categories: Publications|Tags: |

Surface materials with specific wettability play important roles in a wide variety of areas from science to industry. We present a novel paraffin-infused porous graphene film (PIPGF) with programmable wettability. Because of graphene’s photothermal property, the paraffin in the PIPGF was in transition between liquid and solid in response to

Published in: "Science Advances".

In situ manipulation and switching of dislocations in bilayer graphene

2018-08-11T00:36:40+00:00August 11th, 2018|Categories: Publications|Tags: |

Topological defects in crystalline solids are of fundamental interest in physics and materials science because they can radically alter the properties of virtually any material. Of particular importance are line defects, known as dislocations, which are the main carriers of plasticity and have a tremendous effect on electronic and optical

Published in: "Science Advances".

Coherent perfect absorption of nonlinear matter waves

2018-08-11T00:36:37+00:00August 11th, 2018|Categories: Publications|Tags: |

Coherent perfect absorption is the complete extinction of incoming radiation by a complex potential in a physical system supporting wave propagation. The concept was proven for linear waves in a variety of systems including light interacting with absorbing scatterers, plasmonic metasurfaces, and graphene films, as well as sound waves. We

Published in: "Science Advances".

Hidden CDW states and insulator-to-metal transition after a pulsed femtosecond laser excitation in layered chalcogenide 1T-TaS2-xSex

2018-07-20T18:36:21+00:00July 20th, 2018|Categories: Publications|Tags: , |

The hidden (H) quantum state in 1T-TaS2 has sparked considerable interest in the field of correlated electron systems. Here, we investigate ultrafast switches to stable H charge density wave (H-CDW) states observed in 1T-TaS2–xSex, with x = 0 and 0.5 crystals, upon excitation with a single femtosecond laser pulse. In

Published in: "Science Advances".

Room temperature in-plane ferroelectricity in van der Waals In2Se3

2018-07-14T02:36:22+00:00July 14th, 2018|Categories: Publications|Tags: |

Van der Waals (vdW) assembly of layered materials is a promising paradigm for creating electronic and optoelectronic devices with novel properties. Ferroelectricity in vdW layered materials could enable nonvolatile memory and low-power electronic and optoelectronic switches, but to date, few vdW ferroelectrics have been reported, and few in-plane vdW ferroelectrics

Published in: "Science Advances".

Ultrathin graphdiyne film on graphene through solution-phase van der Waals epitaxy

2018-07-07T00:36:24+00:00July 7th, 2018|Categories: Publications|Tags: |

Graphdiyne (GDY) is an ordered two-dimensional (2D) carbon allotrope comprising sp- and sp2-hybridized carbon atoms with high degrees of -conjugation, which features a natural band gap and superior electric properties. However, the synthesis of one- or few-layer GDY remains challenging because of the free rotation around alkyne-aryl single bonds and

Published in: "Science Advances".

Observation of Poiseuille flow of phonons in black phosphorus

2018-06-22T20:37:01+00:00June 22nd, 2018|Categories: Publications|Tags: |

The travel of heat in insulators is commonly pictured as a flow of phonons scattered along their individual trajectory. In rare circumstances, momentum-conserving collision events dominate, and thermal transport becomes hydrodynamic. One of these cases, dubbed the Poiseuille flow of phonons, can occur in a temperature window just below the

Published in: "Science Advances".

Ultra-confined mid-infrared resonant phonon polaritons in van der Waals nanostructures

2018-06-15T18:36:32+00:00June 15th, 2018|Categories: Publications|Tags: |

Hexagonal boron nitride has been proposed as an excellent candidate to achieve subwavelength infrared light manipulation owing to its polar lattice structure, enabling excitation of low-loss phonon polaritons with hyperbolic dispersion. We show that strongly subwavelength hexagonal boron nitride planar nanostructures can exhibit ultra-confined resonances and local field enhancement. We

Published in: "Science Advances".

Multifunctional structural design of graphene thermoelectrics by Bayesian optimization

2018-06-15T18:36:30+00:00June 15th, 2018|Categories: Publications|Tags: |

Materials development often confronts a dilemma as it needs to satisfy multifunctional, often conflicting, demands. For example, thermoelectric conversion requires high electrical conductivity, a high Seebeck coefficient, and low thermal conductivity, despite the fact that these three properties are normally closely correlated. Nanostructuring techniques have been shown to break the

Published in: "Science Advances".

Oxygen-deficient triple perovskites as highly active and durable bifunctional electrocatalysts for oxygen electrode reactions

2018-06-15T18:36:28+00:00June 15th, 2018|Categories: Publications|Tags: |

Highly active and durable bifunctional oxygen electrocatalysts have been of pivotal importance for renewable energy conversion and storage devices, such as unitized regenerative fuel cells and metal-air batteries. Perovskite-based oxygen electrocatalysts have emerged as promising nonprecious metal bifunctional electrocatalysts, yet their catalytic activity and stability still remain to be improved.

Published in: "Science Advances".

Some say, that 2D Research is the best website in the world.