https://www.nature.com/articles/s41598-023-29122-w
Dynamic and fluctuation properties of a graphene disk levitated by a diamagnetic force in air
and Kazunori Maebuchi1
Published 29 April 2022 • © 2022
https://iopscience.iop.org/article/10.1088/1361-6463/ac683c/meta
A graphene disk can be levitated above a magnet by a repulsive force arising from their diamagnetic interaction if the product of the magnetic field and its gradient is sufficiently large. The diamagnetic force also causes the rotation of the graphene disk because of the strong anisotropy of the magnetic permeability of graphene; thus a motion of centroid and rotation are considered by solving simultaneous Langevin equations.
https://ieeexplore.ieee.org/abstract/document/10102413
Graphene exhibits diamagnetism, enabling it to be lifted by the repulsive force produced in an inhomogeneous magnetic field. However, the stable levitation of a graphene flake perpendicular to the magnetic field is impeded by its strong anisotropic of magnetic susceptibility that induces rotation. A method to suppress this rotation by applying the Casimir force to the graphene flake is presented in this paper. As a result, the graphene flake can archive stable levitation on a silicon plate when the gravitational force is small.
https://www.mdpi.com/2624-8174/5/3/60
11 January 2023: Researchers create an optical tractor beam that pulls macroscopic objects... macroscopic graphene-SiO2 composite objects they designed can be used for laser pulling in a rarefied gas environment. This type of environment has a pressure much lower than atmospheric pressure. For the last ten years, scientists have been working on a new type of optical manipulation: using laser light to create an optical tractor beam that could pull objects....“Our technique provides a non-contact and long-distance pulling approach, which may be useful for various scientific experiments,” said Wang. “The rarefied gas environment we used to demonstrate the technique is similar to what is found on Mars. Therefore, it might have the potential for one day manipulating vehicles or aircraft on Mars.”
This work presents a contactless mothed to massively pull microscale graphene materials in simple liquid, which supplies a potential manipulation technique for micro-nanofluidic devices and also provides a platform to investigate laser-graphene interaction in a simple liquid phase medium.
https://opg.optica.org/oe/fulltext.cfm?uri=oe-31-21-34057&id=540328
Nonlocal resistance in Graphene
long-range response due to due to the fact that that i described one can alsoby measuring at the different pairs of contacts one can also determine length over which you know decays on the length in this case characteristic length in this case is about a micron which in this device coincides with at would its width so that that would be consistent with very very scattering occurring when whenever carries heat hit the boundary and yeah so that's and i mean there is a checklist of what what you expect for valley currents and what you don't expect and we went all over it and they'll be happy to me to discuss and and it all all agrees you expect from for really current you expect to hear scaling a very whole response which is which goes as cube of resistivity and so that's that's that's a check on that and and there is a reasonably good agreement you know a few other things so so the conclusion here is that we we have a way to induce charge neutral currents and detect them by a non-local response and so this is a bonus bonus picture a table gate which which is added on top of this device can be used to shut shut this non-local signal on and off and and the sensitivity the top top gate voltage is pretty pretty strongly you can shut it down fully by applying very strong very weak potential on that top top gate alright and so this is a little bit like you know for people who who are who know spintronics it's a little bit like the proponent that data does proposal of a spin transistor where you put put top gate to the gate to control spin orbit
....................
the non-local non-local voltage measured somewhere here will be negative rather
than positive as you expect an ohmic case and if you do if you do calculation you find that this is indeed true so
this is so what you see here are streamlines these are these white white
curves and the color is potential a blue means negative
https://arxiv.org/ftp/arxiv/papers/2202/2202.02798.pdf
Mechanism of a negative electrical response: viscous shear flow generates vorticity and a backflow on the side of the main current path, which leads to charge buildup of the sign opposing the flow and results in a negative nonlocal voltage.
Transport measurements showing negative nonlocal resistance in the vicinity of the current injection point are suggestive of electron backflow in graphene
https://arxiv.org/pdf/2302.10744.pdf
Strictly speaking, in the device of Fig. 1, energy – rather than momentum – entanglement can be preserved for electrons tunneling to spin polarized leads [1]. This non-local energy entanglement was justified by a Bell-Clauser Horne inequality [33] violation test in Ref. [34].
https://arxiv.org/abs/2206.04565
Here, we report non-local transport measurements in small gap hBN/graphene/hBN moiré superlattices which reveal very strong magnetic field-induced chiral response which is stable up to room temperature. The measured sign dependence of the non-local signal with respect to the magnetic field orientation clearly indicates the manifestation of emerging orbital magnetic moments. The interpretation of experimental data is well supported by numerical simulations, and the reported phenomenon stands as a formidable way of in-situ manipulation of the transverse flow of orbital information, that could enable the design of orbitronic devices.
Generation and control of non-local chiral currents in graphene superlattices
by orbital Hall effect
Indeed, such systems present considerable non-locality [7,
9, 15–17], whose origin, although frequently associated
to the VHE [valley Hall Effect\, is currently strongly debated [18–21]. It has
been shown that doubly aligned hBN/graphene stacks
might generate a super-moiré pattern [22], leading to the
presence of small and non-uniform band gaps [20, 21].
vdW2Ds are, henceforth, a perfect platform for the study
of inversion symmetry breaking in graphene. Because of
the small gaps, the valley orbital magnetic moments are
large and can be manipulated with magnetic and electric
fields.
https://iopscience.iop.org/article/10.1088/1674-1056/26/12/127304
The present study pertains to the trilayer graphene in the presence of spin orbit coupling to probe the quantum spin/valley Hall effect.Valley Hall effect and nonlocal resistance in locally gapped graphene
https://journals.aps.org/prb/abstract/10.1103/PhysRevB.103.115406
5
for the pairs of contacts, compared to Fig. 4a as
sketched in panel Fig. 4c. Consequently, we can argue
that the valley-carrier locking, visible in the non-local
signal, is a quite robust phenomenon and implies a flow
of carriers characterized by different orbital magnetic
moments. As the non-local signal should originate from
the flow of orbital magnetic moments from a single
valley, we compare Rnl with the valley filtered OHE,
calculated according to Ref. [11], shown in the insets
of Figs. 4a and 4b. In conclusion, the interpretation
of the experimental results are very consistent with the
changes in the OHE resulting from the orbital Zeeman
effect. The theoretical calculations indicate that the
observed Zeeman shift is consistent with a graphene gap
of ∆ ∼ 5 − 10 meV. For details on the OHE calculations,
see Sec. 6 of the Supplementary Information.
Figure 5 presents the local and non-local signals
for a configuration where the excitation current lies
symmetrically between two different pairs of contacts for
Rnl at a fixed perpendicular magnetic field of B⊥ = 0.5 T
and variable in-plane component (B‖) measured at 1.5 K.
B‖ ranges from 0 to 12 T and its evolution has been
marked with an arrow as a guide to the eye. When no
parallel magnetic field is applied (B‖ = 0), the charge
carrier type is effectively coupled to one of the valleys and
the asymmetric chiral behavior is found. Distinctively,
while enhancing the in-plane magnetic field component,
both non-local and local signals diminish and become
symmetric. From these data, it becomes clear that the
chiral non-local currents cannot be attributed to a spin-
dependent effect. In-plane magnetic fields can be used
to probe spin-polarized currents, as they lead to a non-
local resistance that oscillates in function of the field
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