A doping-dependent switch from one- to two-component superfluidity at temperature above 100K in coupled electron-hole Van der Waals heterostructures

On superfluidity of indirect excitons in transition metals trichalcogenides van der Waals heterostructures

We predict angle-dependent superfluidity for a new class of 2D materials -- transition metals trichalcogenides (TMTC). Within a mean-field approach superfluidity of indirect excitons in TMTC van der Waals heterostructures (vdWHs) is studied. We use different potentials for charged carriers interaction to analyze the influence of the screening on the studied phenomena. Our study demonstrates the angle-dependent superfluidity temperature in TMTC vdWHs: for a given density a maximum and minimum $T_c$ of superfluidity occurs along chain and $a$-directions, respectively. This work can guide experim…

Josephson effect as signature of electron-hole superfluidity in bilayers of van der Waals heterostructures

We investigate a Josephson junction in an electron-hole superfluid in a double layer TMD heterostructure. Observation of a critical tunneling current is a clear signature of superfluidity. In addition, we find the BCS-BEC crossover physics in the narrow barrier region controls the critical current across the entire system. The corresponding critical velocity, which is measurable in this system, has a maximum when the excitations pass from bosonic to fermionic. Remarkably, this occurs for the density at the boundary of the BEC to BCS-BEC crossover regime determined from the condensate fraction.…

Superfluidity of Helium-3

This article presents a phenomenological dynamic phase transition theory -- modeling and analysis -- for liquid helium-3. We derived two new models, for liquid helium-3 with or without applied field, by introducing three wave functions and using a unified dynamical Ginzburg-Landau model. The analysis of these new models leads to predictions of existence of 1) a unstable region, 2) a new phase C in a narrow region, and 3) switch points of transition types on the coexistence curves near two triple points. It is hoped that these predictions will be useful for designing better physical experiments…

GaSe/NbSe$_2$范德华异质结构中的栅控超导开关

Gate-controlled superconducting switch in GaSe/NbSe$_2$ van der Waals heterostructure

本研究在GaSe/NbSe$_2$范德华异质结构中实现了一种栅控超导开关，通过电场注入高能电子诱导非平衡态并利用铁电极化实现陡峭亚阈值斜率，可逆切换超导态与正常态，为超导集成电路提供了新方案。

超快太赫兹超导体范德华超材料光子开关

Ultrafast terahertz superconductor van der Waals metamaterial photonic switch

本研究设计了基于高温超导BSCCO范德华材料的超快太赫兹超材料光子开关，实现相位和幅度调制，开关时间50皮秒，并探讨了光-物质相互作用动力学，适用于通信和量子技术。

二维双层电子-空穴超流性与不等及各向异性质量

2D bilayer electron-hole superfluidity with unequal and anisotropic masses

研究了二维双层中电子-空穴超流性在不等和各向异性质量下的稳定性，发现质量不匹配和各向异性会降低配对强度并抑制临界温度，但超流性仍保持稳健。