A non-perturbative field theory approach for the Kondo effect: Emergence of an extra dimension and its implication for the holographic duality conjecture

Implementing Wilsonian renormalization group transformations in an iterative way, we develop a non-perturbative field theoretical framework, which takes into account all-loop quantum corrections organized in the $1/N$ expansion, where $N$ represents the flavor number of quantum fields. The resulting classical field theory is given by an effective Landau-Ginzburg theory for a local order parameter field, which appears in one-dimensional higher spacetime. We claim that such all-loop quantum corrections are introduced into an equation of motion for the order parameter field through the evolution in the emergent extra dimension. Based on this non-perturbative theoretical framework, we solve the Kondo effect, where the quantum mechanics problem in the projective formulation is mapped into a Landau-Ginzburg field theory for the hybridization order parameter field with an emergent extra dimension. We confirm the non-perturbative nature of this field theoretical framework. Intriguingly, we show that the Wilsonian renormalization group method can explain non-perturbative thermodynamic properties of an impurity consistent with the Bethe ansatz solutions. Finally, we speculate how our non-perturbative field theoretical framework can be connected with the AdS$_{d+2}$/CFT$_{d+1}$ duality conjecture.Comment: Completely rewritte

Cooper-Pair Spin Current in a Strontium Ruthenate Heterostructure

It has been recognized that the condensation of spin-triplet Cooper pairs requires not only the broken gauge symmetry but also the spin ordering as well. One consequence of this is the possibility of the Cooper-pair spin current analogous to the magnon spin current in magnetic insulators, the analogy also extending to the existence of the Gilbert damping of the collective spin-triplet dynamics. The recently fabricated heterostructure of the thin film of the itinerant ferromagnet SrRuO3 on the bulk Sr2RuO4, the best-known candidate material for the spin-triplet superconductor, offers a promising platform for generating such spin current. We will show how such heterostructure allows us to not only realize the long-range spin valve but also electrically drive the collective spin mode of the spin-triplet order parameter. Our proposal represents both a new realization of the spin superfluidity and a transport signature of the spin-triplet superconductivity.Comment: 5 pages, 3 figure

Unintended complication of intracranial subdural hematoma after percutaneous epidural neuroplasty.

Percutaneous epidural neuroplasty (PEN) is a known interventional technique for the management of spinal pain. As with any procedures, PEN is associated with complications ranging from mild to more serious ones. We present a case of intracranial subdural hematoma after PEN requiring surgical evacuation. We review the relevant literature and discuss possible complications of PEN and patholophysiology of intracranial subdural hematoma after PEN

Magnon topology and thermal Hall effect in trimerized triangular lattice antiferromagnet

The non-trivial magnon band topology and its consequent responses have been extensively studied in two-dimensional magnetisms. However, the triangular lattice antiferromagnet (TLAF), the best-known frustrated two-dimensional magnet, has received less attention than the closely related Kagome system, because of the spin-chirality cancellation in the umbrella ground state of the undistorted TLAF. In this work, we study the band topology and the thermal Hall effect (THE) of the TLAF with (anti-)trimerization distortion under the external perpendicular magnetic field using the linearized spin wave theory. We show that the spin-chirality cancellation is removed in such case, giving rise to the non-trivial magnon band topology and the finite THE. Moreover, the magnon bands exhibit band topology transitions tuned by the magnetic field. We demonstrate that such transitions are accompanied by the logarithmic divergence of the first derivative of the thermal Hall conductivity. Finally, we examine the above consequences by calculating the THE in the hexagonal manganite YMnO$_3$, well known to have anti-trimerization.Comment: 6 + 7 pages, 3 + 5 figures, 0 + 1 table; Journal reference adde

Competing states for the fractional quantum Hall effect in the 1/3-filled second Landau level

In this work, we investigate the nature of the fractional quantum Hall state in the 1/3-filled second Landau level (SLL) at filling factor $\nu=7/3$ (and 8/3 in the presence of the particle-hole symmetry) via exact diagonalization in both torus and spherical geometries. Specifically, we compute the overlap between the exact 7/3 ground state and various competing states including (i) the Laughlin state, (ii) the fermionic Haffnian state, (iii) the antisymmetrized product state of two composite fermion seas at 1/6 filling, and (iv) the particle-hole (PH) conjugate of the $Z_4$ parafermion state. All these trial states are constructed according to a guiding principle called the bilayer mapping approach, where a trial state is obtained as the antisymmetrized projection of a bilayer quantum Hall state with interlayer distance $d$ as a variational parameter. Under the proper understanding of the ground-state degeneracy in the torus geometry, the $Z_4$ parafermion state can be obtained as the antisymmetrized projection of the Halperin (330) state. Similarly, it is proved in this work that the fermionic Haffnian state can be obtained as the antisymmetrized projection of the Halperin (551) state. It is shown that, while extremely accurate at sufficiently large positive Haldane pseudopotential variation $\delta V_1^{(1)}$, the Laughlin state loses its overlap with the exact 7/3 ground state significantly at $\delta V_1^{(1)} \simeq 0$. At slightly negative $\delta V_1^{(1)}$, it is shown that the PH-conjugated $Z_4$ parafermion state has a substantial overlap with the exact 7/3 ground state, which is the highest among the above four trial states.Comment: 22 pages, 5 figure

Call Timing of Callable Non-Convertible Bonds: A Survival Analysis

We empirically analyze the factors affecting corporate decisions to call non-convertible bonds using survival analysis. The results show that firms tend to defer calling non-convertible bonds in order to mitigate agency costs of debt (including under-investment and risk-shift); that calling is significantly more intense if positive information is revealed; that non-refundability clauses are binding on call decisions; that firms are more likely to redeem bonds to refund if market interest rates fall dramatically; and that this interest effect is stronger as the transaction costs of refunding decrease. Also, this paper shows that call intensity monotonically decreases after call protection periods expire

Horizontal linear vibrating actuator to reduce smart phone thickness

Smart phones have numerous features and large display. In result, the smart phone is less portable than before due to its large size. In order to improve the portability of a smart phone, the thickness of the smart phone should be reduced. This is one of the important issues in today's smart phone hardware industry. The vibrating actuator is the thickest component in a smart phone. A thinner electric vibration actuator could make smart phones slimmer. Currently, a vertical linear vibrating actuator is used in smart phones, and it vibrates in the thickness direction of the phone. This imposes a restriction on the sliming of smart phones. Also, a vertical actuator has a thickness of approximately 3.0 to 3.6 mm. We develop a horizontal linear vibrating actuator that can be used to reduce the thickness of a smart phone. Mathematical vibration modeling is used to calculate the magnetic force, and a finite element analysis using the commercial electromagnetic analysis software MAXWELL is performed to determine the specifications of a permanent magnet and electromagnetic coil. The guide spring is designed by modal and harmonic response analysis using ANSYS. A horizontal linear vibrating actuator is designed, and a prototype is manufactured for use in experiments. Its thickness is reduced by 30 % compared to a vertical linear vibrating actuator. In addition, the actuator can vibrate with an acceleration of up to 2.10 Gravity (G), which represents an improvement of at least 40 % compared to a vertical linear vibrating actuator

Dynamic experiment of active accelerator pedal system with a coreless tubular electromagnetic linear actuator

An automobile active accelerator pedal (AAP) warns the driver about an emergency. A tubular electromagnetic linear actuator is the key component to create an impact or vibration, but it has a large cogging force due to a steel core that causes instabilities. Accordingly, we propose an AAP with a coreless tubular electromagnetic linear actuator, and verify its performance using dynamic experiments