3,012 research outputs found
Tunable valley and spin splittings in bilayer
The control and manipulation of the valley and spin degrees of freedom have
received great interests in fundamental studies and advanced information
technologies. Compared with magnetic means, it is highly desirable to realize
more energy-efficient electric control of valley and spin. Using the
first-principles calculations, we demonstrate tunable valley and spin
degeneracy splittings in bilayers, with the aid of the layered
structure and associated electric control. Depending on different interlayer
magnetic couplings and stacking orders, the bilayers exhibit a
variety of combinations of valley and spin degeneracies. Under the action of a
vertical electric field, the degeneracy splittings become highly tunable for
both the sign and magnitude. As a result, a series of anomalous Hall currents
can be selectively realized with varied indices of valley and spin. These
intriguing features offer a practical way for designing energy-efficient
devices based on the couplings between multiple electronic degrees of freedom.Comment: 7 pages, 5 figure
Rabi Spectroscopy of Super-Bloch Oscillations in Optical Lattice Clock
Super-Bloch oscillations(SBOs) is giant Bloch oscillations (BOs) when
applying both static and periodically driving force to free atoms in lattice at
the condition that Bloch oscillations are close to integer times of driving
frequencies. Rather than observe SBOs in real space, this paper presents a
method to observe it using Rabi spectroscopy of Optical lattice clock(OLC). An
effective model of OLC with atoms been added both static and time-periodical
forces is derived. Based on that, we propose an experimental scheme and give
the Rabi spectrum under lab achievable parameters. Utilizing the precision
spectroscopy of OLC, force with a large range could be accurately measured by
measuring the Period of SBOs. We also gave the best parameter condition of
measuring gravity by calculating Fisher information. Our work paves the way to
study other exotic dynamics behaviors in Floquet driving OLC
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