介观与纳米尺度物理
Quasi-optical experiments are emerging as a powerful technique to probe magnetic transitions in molecular spin systems. However, the simultaneous presence of the electric- and magnetic-dipole induced transitions poses the challenge of…
A theory of dynamic polarization of the nuclear spin system via optically-oriented charge carriers in lead halide perovskites is developed and compared with the experiments performed on a FA$_{0.9}$Cs$_{0.1}$PbI$_{2.8}$Br$_{0.2}$ crystal.…
Zero indirect gaps in band models are typically viewed as unstable and achievable only through fine-tuning. Recent works, however, have revealed robust semimetallic phases in Hermitian systems where the indirect gap remains pinned at zero…
It is of great interest to develop methods to rapidly and effectively control the magnetic configurations in artificial spin ices, which are arrangements of dipolar coupled nanomagnets that have a variety of fascinating collective magnetic…
Controlling the alignment of two dimensional (2D) materials is crucial for optimizing their electronic and mechanical properties in next generation devices. This study explores how electric fields can manipulate the orientation of 2D…
Collinear antiferromagnets with nonrelativistic spin-split bands and no net magnetization, called altermagnets, show interesting transport properties due to their unique band structure. We here compute the linear response optical…
We uncover a chain of nonlinear modal interactions in softly clamped nanostring resonators. The process involves the sequential coupling of five mechanical modes, during frequency sweeps, yielding a broad nonlinear response with nearly…
Chains of triangular nanographene (triangulene), recently identified as realizing the valence-bond solid phase of a spin-1 chain, offer a promising platform for quantum information processing. We propose a spin-singlet qubit based on these…
Arrays of Josephson junctions can be tuned through anomalous metallic, quantum-critical, and insulating regimes. We introduce a new experimental probe, capturing microwave radiation across all three regimes, using a two-dimensional array of…
Noncollinear antiferromagnets can generate a transverse electrical response known as the anomalous Hall effect, even though they possess almost no net magnetization. The microscopic origin of this behaviour, however, has remained unclear…
Discrete time crystals (DTCs) are emergent non-equilibrium phases of periodically driven many-body systems, with potential applications ranging from quantum computing to sensing and metrology. There has been significant recent interest in…
The ability to tune quantum tunneling is key for achieving selectivity in manipulation of individual particles in quantum technology applications. In this work we count electron escape events out of a time-dependent confinement potential,…
The emergence of the terahertz (THz) ratchet effect is a rapidly expanding field of research that utilizes broken spatial symmetry in low-dimensional materials to rectify alternating current (AC) induced by THz fields into direct current…
We theoretically investigate spin-valley-locked tunneling transport in a transition-metal dichalcogenide/ferromagnetic-insulator heterostructure under a perpendicular magnetic field, driven by the spin Seebeck effect. We demonstrate that…
We theoretically propose and experimentally demonstrate optically tunable nonlinear mechanical damping in a cavity optomechanical system utilizing a partly resolved sideband regime. Optomechanical coupling provides a delayed nonlinear…
Wavefront dislocations (WDs) -- phase singularities observed in quasiparticle interference (QPI) experiments -- have been widely interpreted as the definitive real-space signatures of Berry phases in graphene-family systems. Here, we…
We investigate the two-port scattering process in non-Hermitian dimer models via quantum measurements using external leads. We focus on two exemplary dimer models that preserve parity-time symmetry via spatial gain-loss balance and exhibit…
In this work we present a cavity-enhanced InAs/$\mathrm{In_{0.53}Al_{0.23}Ga_{0.24}As}$ quantum dot (QD) single-photon source in the telecom C-band with a record-low biexciton emitter decay time of \SI{67.4(2)}{ps} under resonant two-photon…
We show that periodic honeycomb networks of ballistic conducting channels generically host exact flat bands spanning the entire Brillouin zone. These flat bands are independent of microscopic vertex scattering, persist for any number of…
We investigate the topological electronic properties of the $K_4$ crystal by constructing a tight-binding model. The bulk band structure hosts Weyl nodes with higher and conventional chiralities ($\chi = \pm 2$ and $\chi = \pm 1$) located…