3 research outputs found
Electrical-Field Modulation of the Charge-Density-Wave Quantum Condensate in h-BN/NbS Heterostructure Devices
We report on the field-effect modulation of the charge-density-wave quantum
condensate in the top-gated heterostructure devices implemented with
quasi-one-dimensional NbS nanowire channels and quasi-two-dimensional h-BN
gate dielectric layers. The charge-density-wave phases and collective current
in quasi-1D NbS nanowires were verified via temperature dependence of the
resistivity, non-linear current-voltage characteristics, and Shapiro steps that
appeared in the device response under radio frequency excitation mixed with the
DC bias. It was demonstrated that the electric field of the applied gate bias
can reversibly modulate the collective current of the sliding
charge-density-wave condensate. The collective current reduces with more
positive bias suggesting a surface effect on the condensate mobility. The
single particle current, at small source-drain biases, shows small amplitude
fluctuation behavior, attributed to the variations in the background potential
due to the pinned or creeping charge-density-wave condensate. The knowledge of
the electric-field effect on the charge density waves in quasi-1D NbS
nanowires is useful for potential electronic applications of such quantum
materials.Comment: 17 pages; 5 figure
Specifics of the Elemental Excitations in "True One-Dimensional" MoI van der Waals Nanowires
We report on the temperature evolution of the polarization-dependent Raman
spectrum of exfoliated MoI, a van der Waals material with a "true
one-dimensional" crystal structure that can be exfoliated to individual atomic
chains. The temperature evolution of several Raman features reveals anomalous
behavior suggesting a phase transition of a magnetic origin. Theoretical
considerations indicate that MoI is an easy-plane antiferromagnet with
alternating spins along the dimerized chains and with inter-chain helical spin
ordering. The calculated frequencies of the phonons and magnons are consistent
with the interpretation of the experimental Raman data. The obtained results
shed light on the specifics of the phononic and magnonic states in MoI and
provide a strong motivation for future study of this unique material with
potential for spintronic device applications.Comment: 28 page