Related papers: Electrically Tunable Terahertz Chirality from Quan…
We report an observation of a topologically protected transport of surface carriers in a quasi-ballistic Cd3As2 nanowire.The nanowire is thin enough for the spin-textured surface carriers to form 1D subbands, demonstrating conductance…
The geometric phase (Berry phase) of an electronic wave function is the fundamental basis of the topological properties in solids. Modulating band structure provides a tuning knob for the Berry phase, and in the extreme case drives a…
Nonlinear transport enabled by symmetry breaking in quantum materials has aroused considerable interest in condensed matter physics and interdisciplinary electronics. However, the nonlinear optical response in centrosymmetric Dirac…
Surface states of a topological insulator demonstrate interesting quantum phenomena, such as the quantum anomalous Hall (QAH) effect and the quantum magnetoelectric effect. Fermi energy tuning plays a role in inducing phase transitions and…
Electrostatic doping in materials can lead to various exciting electronic properties, such as metal-insulator transition and superconductivity, by altering the Fermi level position or introducing exotic phases. Cd3As2, a three-dimensional…
Quantum materials are characterized by electromagnetic responses intrinsically linked to the geometry and topology of electronic wavefunctions, encoded in the quantum metric and Berry curvature. Whereas Berry curvature-mediated transport…
A grand challenge underlies the entire field of topology-enabled quantum logic and information science: how to establish topological control principles driven by quantum coherence and understand the time-dependence of such periodic driving?…
In two-dimensional layered quantum materials, the stacking order of the layers determines both the crystalline symmetry and electronic properties such as the Berry curvature, topology and electron correlation. Electrical stimuli can…
Electrons on Fermi arcs (FAs), a hallmark of Weyl semimetals, exhibit chiral transport harboring chiral anomaly, negative magnetoresistance, and Majorana zero modes. While FAs were observed in exemplary Weyl semimetal TaAs and Co3Sn2S2, the…
Unconventional surface states protected by non-trivial bulk orders are sources of various exotic quantum transport in topological materials. One prominent example is the unique magnetic orbit, so-called Weyl orbit, in topological semimetals…
We demonstrate a tunable Dirac-Weyl semimetal phase in two dimensions, realized by introducing in-plane d-wave altermagnetism into a Dirac system. This phase hosts both a central Dirac point and momentumseparated Weyl points connected by…
We study the orbital Hall response in buckled two-dimensional Dirac materials using a unified framework that includes an antiferromagnetic exchange field, a perpendicular electric field, and intrinsic spin-orbit coupling. We show that the…
Controlling collective electronic phases in low-dimensional materials is a central challenge for developing technologies based on charge-density waves. Here, we report that perpendicular electric and magnetic fields can be used to tune…
We investigate the quantum geometric tensor, which is comprised of the Berry curvature and quantum metric, in a generalized Dirac two-band system with non-integer dispersion $E(\mathbf{k})\sim k^{\alpha}$. Our analysis reveals that this…
Topological semimetals are three-dimensional topological states of matter, in which the conduction and valence bands touch at a finite number of points, i.e., the Weyl nodes. Topological semimetals host paired monopoles and antimonopoles of…
We theoretically investigate the optical functionality of a semiconducting quantum ring manipulated by two electrostatic lateral gates used to induce a double quantum well along the ring. The well parameters and corresponding inter-level…
Crystal symmetry governs the nature of electronic Bloch states. For example, in the presence of time reversal symmetry, the orbital magnetic moment and Berry curvature of the Bloch states must vanish unless inversion symmetry is broken. In…
We present a systematic microscopic derivation of the semiclassical Boltzmann equation for band structures with the finite Berry curvature based on Keldysh technique of nonequilibrium systems. In the analysis, an ac electrical driving field…
Full experimental control of local spin-charge interconversion is of primary interest for spintronics. Heterostructures combining graphene with a strongly spin-orbit coupled two-dimensional (2D) material enable such functionality by design.…
Compact, electrically driven sources of coherent terahertz (THz) radiation remain a challenge due to the lack of efficient gain media and scalable device platforms. Here, we propose and theoretically investigate a cavity-based THz gain…