77 research outputs found
Magnetism in twisted triangular bilayer graphene quantum dots
Using a tight-binding model along with the mean-field Hubbard method, we
investigate the effect of twisting angle on the magnetic properties of twisted
bilayer graphene (tBLG) quantum dots (QDs) with triangular shape and zigzag
edges. We consider such QDs in two configurations: when their initial untwisted
structure is a perfect AA- or AB-stacked BLG, referred to as AA- or AB-like
dots. We find that AA-like dots exhibit an antiferromagnetic spin polarization
for small twist angles, which transits to a ferromagnetic spin polarization
beyond a critical twisting angle . Our analysis shows that
decreases as the dot size increases, obeying a criterion, according to which
once the maximum energy difference between electron and hole edge states (in
the single-particle picture) is less than , the
spin-polarized energy levels are aligned ferromagnetically [ is the Hubbard
parameter and () the graphene intralayer (interlayer) hopping].
Unlike AA-like dots, AB-like dots exhibit finite magnetization for any twist
angle. Furthermore, in the ferromagnetic polarization state, the ground net
spin for both dot configurations agrees with prediction from Lieb's theorem
Triangulated Surfaces in Twistor Space: A Kinematical Set up for Open/Closed String Duality
We exploit the properties of the three-dimensional hyperbolic space to
discuss a simplicial setting for open/closed string duality based on (random)
Regge triangulations decorated with null twistorial fields. We explicitly show
that the twistorial N-points function, describing Dirichlet correlations over
the moduli space of open N-bordered genus g surfaces, is naturally mapped into
the Witten-Kontsevich intersection theory over the moduli space of N-pointed
closed Riemann surfaces of the same genus. We also discuss various aspects of
the geometrical setting which connects this model to PSL(2,C) Chern-Simons
theory.Comment: 35 pages, references added, slightly revised introductio
Electronic Mach-Zehnder interference in a bipolar hybrid monolayer-bilayer graphene junction
Graphene matter in a strong magnetic field, realizing one-dimensional quantum
Hall channels, provides a unique platform for studying electron interference.
Here, using the Landauer-B\"uttiker formalism along with the tight-binding
model, we investigate the quantum Hall (QH) effects in unipolar and bipolar
monolayer-bilayer graphene (MLG-BLG) junctions. We find that a Hall bar made of
an armchair MLG-BLG junction in the bipolar regime results in valley-polarized
edge-channel interferences and can operate a fully tunable Mach-Zehnder (MZ)
interferometer device. Investigation of the bar-width and magnetic-field
dependence of the conductance oscillations shows that the MZ interference in
such structures can be drastically affected by the type of (zigzag) edge
termination of the second layer in the BLG region [composed of vertical dimer
or non-dimer atoms]. Our findings reveal that both interfaces exhibit a double
set of Aharonov-Bohm interferences, with the one between two oppositely
valley-polarized edge channels dominating and causing a large-amplitude
conductance oscillation ranging from 0 to . We explain and analyze
our findings by analytically solving the Dirac-Weyl equation for a gated
semi-infinite MLG-BLG junction.Comment: 12 pages, 10 figure
Pharmacogenetics in electroconvulsive therapy and adjunctive medications
Personalised Therapeutic
Erratum: Investigation of dynamic and static recrystallization behavior during thermomechanical processing in API-X70 microalloyed steel (Journal of Materials Engineering and Performance DOI: 10.1007/s11665-008-9338-x)
Prediction of Temperature Distribution in the Hot Torsion Test Specimen
Hot torsion test (HTT) has extensively been used to analysis and physically model flow behavior and microstructure evolution of materials and alloys during hot deformation processes. In this test, the specimen geometry has a great influence in obtaining reliable test results. In this paper, the interaction of thermal-mechanical conditions and geometry of the HTT specimen was studied. The commercial finite element package ANSYS was utilized for prediction of temperature distribution during reheating treatment and a thermo-rigid viscoplastic FE code, THORAX.FOR, was used to predict thermo-mechanical parameters during the test for API-X70 micro alloyed steel. Simulation results show that no proper geometry and dimension selection result in non uniform temperature within specimen and predicted to have effects on the consequence assessment of material behavior during hot deformation. Recommendations on finding proper specimen geometry for reducing temperature gradient along the gauge part of specimen will be given to create homogeneous temperature as much as possible in order to avoid uncertainty in consequent results of HTT
Aberrant CYP2D6 metabolizer phenotypes do not show increased frequency in patients undergoing ECT after antidepressant therapy
Personalised Therapeutic
Using PCR-SSCP technique to investigate polymorphism of leptin gene in Kermani sheep
شناسایی ژنهاي موثر بر تعادل انرژي، تولید شیر و مصرف خوراك از علاقهمنديهاي اخیر پژوهشگران اصلاح نژاداست. در ایران علی رغم وجود منابع غنی حیوانی، تلاشهاي اندکی براي شناسایی ژنهاي کنترل کنندهي صفات درآنها صورت گرفته است. بنابراین، شناسایی ژنهاي کاندیداي موثر بر صفات اقتصادي میتواند به اصلاح نژاد گوسفنددر کشور کمک شایانی نماید. در این تحقیق براي بررسی چند شکلی ژن لپتین از 120 رأس گوسفند نر و مادهي کرمانیایستگاه اصلاح نژاد شهر بابک خونگیري شد. پس از استخراج DNA با استفاده از کیت استخراج استاندارد، واکنشزنجیرهاي پلیمراز براي تکثیر قطعهي 275 جفت بازي از اگزون سوم این ژن انجام شد. پس از تعیین چند شکلی فضاییتکرشتهاي، محصولات PCR ،الگوهاي باندي مربوط به ژن لپتین با استفاده از ژل آکریل آمید و رنگ آمیزي نیترات،A/B/F ،A/B/E ،A/B/C ،A/C ،A/B ،C/C ،A/A الگوي 10 ،مطالعه مورد نمونهي در لپتین ژن براي. آمد بدست، نقرهF/C/A ،E/D/B/A وF/C/B/A بدست آمد که نشان دهندهي چندشکلی بالاي در ژن لپتین گوسفندان نژاد کرمانی می-باشد
Minimum Effective Doses of Succinylcholine and Rocuronium During Electroconvulsive Therapy: A Prospective, Randomized, Crossover Trial
Personalised Therapeutic
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