Modeling multiorbital effects in Sr2IrO4 under strain and a Zeeman field

In-situ strain-tuning of the metal-insulator-transition of Ca$_{2}$RuO$_{4}$ in angle-resolved photoemission experiments

We report the evolution of the $k$-space electronic structure of lightly doped bulk Ca$_{2}$RuO$_{4}$ with uniaxial strain. Using ultrathin plate-like crystals, we achieve strain levels up to $-4.1\%$, sufficient to suppress the Mott phase and access the previously unexplored metallic state at low temperature. Angle-resolved photoemission experiments performed while tuning the uniaxial strain reveal that metallicity emerges from a marked redistribution of charge within the Ru $t_{2g}$ shell, accompanied by a sudden collapse of the spectral weight in the lower Hubbard band and the emergence of …

Cooperative Effects of Strain and Electron Correlation in Epitaxial VO2 and NbO2

We investigate the electronic structure of the epitaxial VO$_2$ films in the rutile phase using the density functional theory combined with the slave spin method (DFT+SS). In DFT-SS, the multiorbital Hubbard interactions are added to a DFT-fit tight-binding model, and we employ the slave-spin method to treat the electron correlation. We find that while stretching the system along the rutile $c$-axis results in a band structure favoring an anisotropic orbital fillings, the electron correlation favors an equal electron filling among $t_{2g}$ orbitals. These two distinct effects cooperatively ind…

Zero-modes and global antiferromagnetism in strained graphene

A novel magnetic ground state is reported for the Hubbard Hamiltonian in strained graphene. When the chemical potential lies close to the Dirac point, the ground state exhibits locally both the Néel and ferromagnetic orders, even for weak Hubbard interaction. Whereas the Néel order parameter remains of the same sign in the entire system, the magnetization at the boundary takes the opposite sign from the bulk. The total magnetization this way vanishes, and the magnetic ground state is globally only an antiferromagnet. This peculiar ordering stems from the nature of the strain-induced single par…

磁声共振理论用于探测晶场四重态的多极效应

Theory of Magnetoacoustic Resonance to Probe Multipole Effects Due to a Crystal Field Quartet

本文提出一种通过声波驱动共振探测八极和隐藏的四极自由度的方法，通过各向异性共振跃迁率和Zeeman分裂探讨四极-应变耦合及八极效应。

大赝磁场下的激子

Excitons under large pseudomagnetic fields

本研究利用可调单轴应变在TMDs中产生超过40 Tesla的赝磁场，展示了Zeeman效应和Larmor进动的赝自旋类似物，揭示了激子的玻色子本质，为探测多体态和实现赝自旋器件奠定了基础。

双层镍酸盐中密度波与超导电性竞争的结构对称性效应

Structural symmetry effects on the competition of density waves and superconductivity in bilayer nickelates

利用泛函重整化群研究双层镍酸盐La3Ni2O7中自旋密度波与超导电性的竞争，发现晶格对称性（正交性抑制）是调控有序态的关键，单轴应变可稳定常压超导。