اشترك بالحزمة الذهبية واحصل على وصول غير محدود شمرا أكاديميا
تسجيل مستخدم جديدTransient degrees of freedom and stability
70
0
0.0
(
0
)
اسأل ChatGPT حول البحث
ﻻ يوجد ملخص باللغة العربية
The mechanical stability of a physical system plays a crucial role in determining its excitations and response to strain. Recent advances have led to protocols that can create particularly stable amorphous solids. Such systems, whether they be physical systems created using vapor-deposition or numerical model systems created using swap or breathing algorithms, exist in exceptionally deep energy minima marked by the absence of low-frequency quasilocalized modes. We introduce new numerical protocols for creating stable jammed packings that first introduce and subsequently remove degrees of freedom such as particle sizes or particle stiffnesses. We find that different choices for the degrees of freedom can lead to very different results. For jammed packings, degrees of freedom that couple to the jamming transition, e.g., particle sizes, push the system to much more stable and deeper energy minima than those that only couple to interaction stiffnesses.
قيم البحث
اقرأ أيضاً
We show experimentally that in a supercooled liquid composed of molecules with internal degrees of freedom the internal modes contribute to the frequency dependent shear viscosity and damping of transverse phonons, which results in an additional broa
dening of the transverse Brillouin lines. Earlier, only the effect of internal modes on the frequency dependent bulk viscosity and damping of longitudinal phonons was observed and explained theoretically in the limit of weak coupling of internal degrees of freedom to translational motion. A new theory is needed to describe this new effect. We also demonstrate, that the contributions of structural relaxation and internal processes to the width of the Brillouin lines can be separated by measurements under high pressure.
We measure the renormalized effective mass (m*) of interacting two-dimensional electrons confined to an AlAs quantum well while we control their distribution between two spin and two valley subbands. We observe a marked contrast between the spin and
valley degrees of freedom: When electrons occupy two spin subbands, m* strongly depends on the valley occupation, but not vice versa. Combining our m* data with the measured spin and valley susceptibilities, we find that the renormalized effective Lande g-factor strongly depends on valley occupation, but the renormalized conduction-band deformation potential is nearly independent of the spin occupation.
Novel materials incorporating electronic degrees of freedom other than charge, including spin, orbital or valley textit{et al} have manifested themselves to be of the great interests and applicable potentials. Recently, the multipolar degrees of free
dom have attracted remarkable attention in the electronic correlated effects. In this work, we systematically studied the transport, magnetic and thermodynamic properties of the topological semimetal candidate PrBi in the framework of crystalline electric field theory. Our results demonstrate the $Gamma_3$ non-Kramers doublet as the ground state of Pr$^{3+}$ (4$f^2$) ions. This ground state is nonmagnetic but carries a non-zero quadrupolar moment $langlehat{O}_2^0rangle$. A quadrupolar phase transition is inferred below 0.08 K. No obvious quadrupolar Kondo effect can be identified. Ultrahigh-field quantum oscillation measurements confirm PrBi as a semimetal with non-trivial Berry phase and low total carrier density 0.06 /f.u. We discuss the interplay between low carrier density and $4f^2$ quadrupolar moment, and ascribe the weak quadrupolar ordering and Kondo effect to consequences of the low carrier density. PrBi, thus, opens a new window to the physics of topology and strongly correlated effect with quadrupolar degrees of freedom in the low-carrier-density limit, evoking the need for a reexamination of the Nozi`{e}res exhaustion problem in the context of multi-channel Kondo effect.
We present a theory of spinor superfluidity in a two-species heteronuclear ultracold fermionic atomic gas consisting of arbitrary half-integer spin and one-half spin atoms. In particular, we focus on the magnetism of the superfluid phase and determin
e the possible phases in the absence of a magnetic field. Our work demonstrates similarities between heteronuclear fermionic superfluids and spinor Bose-Einstein condensates at the mean-field level. Possible experimental situations are discussed.
From low-temperature Synchrotron X-ray diffraction, a precise thermal characterization of octahedral distortions in single phase Ruddlesden-Popper Ca3Mn2O7 is performed. Highly sensitive close-steps temperature dependences of Mn-O-Mn bond angles conn
ecting MnO6 octahedra clearly reveal signature of the spin-ordering in the system. Spin-lattice coupling is thus established via the structural distortions responsible for evolution of the magnetic state. Further, temperature anomalies observed here in volume and polarization-measure of the unit cell highlight the interplay between spin, lattice and charge degrees of freedom. Dipole-relaxation characteristics examined under applied magnetic field consistently corroborate the concurrent magnetic and structural changes, in terms of genuine and intrinsic magneto-dielectricity.
سجل دخول لتتمكن من نشر تعليقات
التعليقات
جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
