We investigate the second-order anomalous Hall response in two-dimensional higher-wave symmetric magnets, including the recently discovered class of collinear magnets known as altermagnets, when subjected to a symmetry-breaking external electric field. In these systems, the first- and second-order anomalous Hall responses mediated by the first- and second-order multipoles of the Berry curvature over the occupied states vanish by symmetry. However, a symmetry-breaking dc electric field can induce a nonzero Berry curvature dipole by coupling to a non-vanishing quantum metric, also known as the Berry connection polarizability. An applied ac electric field can then generate a finite nonlinear transverse Hall effect characterized by a second harmonic response. In addition, the dc field itself can generate a finite third-order transverse Hall response. We discuss this remarkable effect in a class of higher-order symmetric unconventional magnets (of $p$, $d$, $f$, $g$, $i$ symmetry), including the subclass of altermagnets. We demonstrate that the electric-field-induced anomalous Hall effect in the higher-wave-symmetric magnets can serve not only as a probe of the underlying quantum metric of the occupied states but also as a means to distinguish the even ($d$-,$g$-wave) and odd ($p$-wave) order parameter symmetries defined on the square lattice.
Kenta Suzuki, Yasuaki Mizoguchi, Fumihiko Kimura
et al.
Abstract Suzuki, K, Mizoguchi, Y, Kimura, F, Fujisaki, K, Yokoyama, D, Hall, T, and Akasaka, K. Correlation between muscle strength, swing speed, batting statistics, and body composition parameters in high school baseball players: a retrospective observational study. J Strength Cond Res 39(2): e135–e141, 2025—Body composition has emerged as a pivotal factor influencing baseball player performance. The purpose of this study was to examine the relationships between muscle strength, swing speed, batting statistics, and body composition in high school baseball players. This retrospective study evaluated 29 high school baseball players included critical parameters related to body composition (body fat percentage, lean body mass [LBM], fat mass index [FMI], and fat-free mass index [FFMI]), muscle strength (bench press, squat, deadlift), batting statistics (batting average, on-base percentage, slugging percentage, on-base plus slugging), and swing speed. These metrics were gathered using a body composition analyzer (Omron HBF-701; Omron Healthcare Co., Kyoto, Japan). After the correlation analysis with body composition, a subsequent multivariate analysis was conducted. Multivariate regression analysis identified LBM (p < 0.05, p < 0.01) as a significant predictor for bench press and swing speed, FFMI for squat (p < 0.01), and FMI for deadlift (p < 0.05). No significant association was found between body composition and batting statistics. Lean body mass has been identified as an important contributing factor to swing speed, suggesting the need for body composition management among high school baseball players and coaches to enhance performance and functionality. However, no association was found between batting statistics and body composition. Therefore, it is suggested that high school baseball players prioritize the development of technical skills over swing speed and muscle strength to improve batting statistics.
Dmitry V. Chichinadze, Naiyuan James Zhang, Jiang-Xiazi Lin
et al.
In a system of two-dimensional electrons, a combination of broken symmetry, interactions, and nontrivial topology can conspire to give rise to a nonlinear transport regime, where electric current density scales as the square of electric field. This regime has become a venue for exciting discoveries such as the nonlinear Hall effect and diode-like nonreciprocal transport. However, interpretation of experimental data is challenging in the nonlinear regime as DC transport is described by a rank-3 conductivity tensor with 6 free parameters. Here, we resolve this challenge by analytically solving for the nonlinear potential distribution across the disk sample for an arbitrary linear and nonlinear conductivity tensors. This allows us to unambiguously extract all components of the nonlinear tensor from experimental measurement. Using this novel tool, we identify giant nonlinear Hall effect in Bernal bilayer graphene. Our methodology provides the first systematic framework for interpreting nonlinear transport and uncovers a new route towards understanding quasi-2D materials.
Supplemental Digital Content is Available in the Text. Abstract Hall, AJ, Aspe, RR, Craig, TP, Kavaliauskas, M, Babraj, J, and Swinton, PA. The effects of sprint interval training on physical performance: a systematic review and meta-analysis. J Strength Cond Res 37(2): 457–481, 2023—The present study aimed to synthesize findings from published research and through meta-analysis quantify the effect of sprint interval training (SIT) and potential moderators on physical performance outcomes (categorized as aerobic, anaerobic, mixed aerobic-anaerobic, or muscular force) with healthy adults, in addition to assessing the methodological quality of included studies and the existence of small study effects. Fifty-five studies were included (50% moderate methodological quality, 42% low methodological quality), with 58% comprising an intervention duration of ≤4 weeks and an array of different training protocols. Bayesian’s meta-analysis of standardized mean differences (SMD) identified a medium effect of improved physical performance with SIT (ES0.5 = 0.52; 95% credible intervals [CrI]: 0.42–0.62). Moderator analyses identified overlap between outcome types with the largest effects estimated for anaerobic outcomes (ES0.5 = 0.61; 95% CrI: 0.48–0.75). Moderator effects were identified for intervention duration, sprint length, and number of sprints performed per session, with larger effects obtained for greater values of each moderator. A substantive number of very large effect sizes (41 SMDs > 2) were identified with additional evidence of extensive small study effects. This meta-analysis demonstrates that short-term SIT interventions are effective for developing moderate improvements in physical performance outcomes. However, extensive small study effects, likely influenced by researchers analyzing many outcomes, suggest potential overestimation of reported effects. Future research should analyze fewer a priori selected outcomes and investigate models to progress SIT interventions for longer-term performance improvements.
Huggins, RA, Fortunati, AR, Curtis, RM, Looney, DP, West, CA, Lee, EC, Fragala, MS, Hall, ML, and Casa, DJ. Monitoring blood biomarkers and training load throughout a collegiate soccer season. J Strength Cond Res XX(X): 000-000, 2018-This observational study aimed to characterize the responses of a comprehensive panel of biomarkers, observed ranges, training load (TL) metrics, and performance throughout the collegiate soccer season (August-November). Biomarkers (n = 92) were collected before the start of pre-season (PS), in-season weeks (W)1, W4, W8, and W12 in NCAA Division I male soccer players (n = 20, mean ± SD; age = 21 ± 1 years, height = 180 ± 6 cm, body mass = 78.19 ± 6.3 kg, body fat = 12.0 ± 2.6%, V[Combining Dot Above]O2max 51.5 ± 5.1 ml·kg·min). Fitness tests were measured at PS, and W12 and TL was monitored daily. Changes in biomarkers and performance were calculated via separate repeated-measures analysis of variance. Despite similar fitness (p > 0.05), endocrine, muscle, inflammatory, and immune markers changed over time (p 0.94 mg·dL). Oxygen transport and iron metabolism markers remained unchanged except for HCT (W1 vs. PS) and total iron binding capacity (W8-W12 vs. W1). Hepatic markers albumin, globulin, albumin:globulin, and total protein levels were elevated (p < 0.05) at W12 vs. W1, whereas aspartate aminotransferase and alanine aminotransferase levels were elevated at W1-W12 and W8-W12 vs. PS, respectively. Vitamin E, zinc, selenium, and calcium levels were elevated (p < 0.05) at W12 vs. W1, whereas Vitamin D was decreased (p < 0.05). Fatty acids and cardiovascular markers (omega-3 index, cholesterol:high-density lipoprotein [HDL], docosahexenoic acid, low-density lipoprotein [LDL], direct LDL, non-HDL, ApoB) were reduced at W1 vs. PS (p ≤ 0.05). Immune, lipid, and muscle damage biomarkers were frequently outside clinical reference ranges. Routine biomarker monitoring revealed subclinical and clinical changes, suggesting soccer-specific reference ranges. Biomarker monitoring may augment positive adaptation and reduce injuries from stressors incurred during soccer.
Exploring exotic interface magnetism due to charge transfer and strong spin-orbit coupling has profound application in future development of spintronic memory. Here, the emergence, tuning and interpretation of hump-shape Hall Effect from a CaMnO3/CaIrO3/CaMnO3 trilayer structure are studied in detail. The hump signal can be recognized as Topological Hall Effect suggesting the presence of Skyrmion-like magnetic bubbles; but the debated alternative interpretation where the signal being an artefact between two cancelling Anomalous Hall Effect loops is also discussed. Firstly, by tilting the magnetic field direction, the evolution of Hall signal suggests transformation of the bubbles topology into a more trivial kind. Secondly, by varying the thickness of CaMnO3, the optimal thicknesses for the hump signal emergence are found, suggesting a tuning of charge transfer fraction. Using high-resolution transmission electron microscopy, a stacking fault is also identified, which distinguishes the top and bottom CaMnO3/CaIrO3 interfaces in terms of charge transfer fraction and possible interfacial Dzyaloshinskii-Moriya Interaction. Finally, a spin-transfer torque experiment revealed a low threshold current density of ~10^9 A/m^2 for initiating the motion of bubbles. This discovery opens a possible route for integrating Skyrmions with antiferromagnetic spintronics.
Abstract Smith, JC, Pridgeon, B, and Hall, MC. Acute effect of foam rolling and dynamic stretching on flexibility and jump height. J Strength Cond Res 32(8): 2209–2215, 2018—Dynamic stretching (DS) can acutely improve vertical jump (VJ) performance but its effect lasts no more than 5 minutes. Foam rolling (FR), a form of self-myofascial release, can acutely increase range of motion (ROM) with this effect lasting less than 10 minutes. Therefore, the purpose of this study was to evaluate the time course of these effects, separately and combined, on VJ height and ROM. Twenty-nine university students completed 4 different sessions (control, FR, DS, and combo) in a randomized order. After a warm-up and baseline assessments of VJ height and sit-and-reach, participants rested (control) and performed FR, DS, and the combination of FR and DS (combo). Vertical jump height and ROM were assessed every 5 minutes for 20 minutes after treatment. Mean scores at each time point were expressed as a percent change from baseline scores. Immediately after FR, sit-and-reach was significantly greater than control (p = 0.003). Vertical jump height immediately after treatment for DS and combo was significantly greater than the control and FR counterparts (p ⩽ 0.002). Vertical jump height for DS and combo was also significantly greater than the control counterpart at 5 minutes after treatment (p < 0.001). At 15 minutes after treatment, the percent change in VJ height for the combo was significantly greater than the control counterpart (p = 0.002). Although FR has no effect on VJ performance, it can acutely increase ROM, but its effect was quickly dissipated. Foam rolling does not seem to enhance VJ height either alone or in combination with DS.
We present a different approach to the fractional quantum Hall effect (FQHE), focusing it as a consequence of the change in the symmetry of the Hamiltonian of every electron in a two-dimensional electron gas (2DEG) under the application of a magnetic field and in the presence of an electrostatic potential due to the ionized impurities, and leading to a breaking of the degeneration of the Landau levels. As the magnetic field increases the effect of that electrostatic potential evolves, changing in turn the spatial symmetry of the Hamiltonian: from continuous to discrete one. The aim of both works is to give a different picture not only of the FQHE phenomenon, but a coherent one with the integer quantum Hall effect (IQHE) and consistent with the model already described in Hidalgo7, 8, 9. Therefore the model gives a global view of both effects, showing that they are aspects of the same phenomenon, and justifying not only the appearance of the odd denominator plateaux but also the even ones; and giving some physical reasons for the experimental fact that there are much more odd than even denominator plateaux, hardly observed
We present three holographic constructions of fractional quantum Hall effect (FQHE) via string theory. The first model studies edge states in FQHE using supersymmetric domain walls in N=6 Chern-Simons theory. We show that D4-branes wrapped on CP^1 or D8-branes wrapped on CP^3 create edge states that shift the rank or the level of the gauge group, respectively. These holographic edge states correctly reproduce the Hall conductivity. The second model presents a holographic dual to the pure U(N)_k (Yang-Mills-)Chern-Simons theory based on a D3-D7 system. Its holography is equivalent to the level-rank duality, which enables us to compute the Hall conductivity and the topological entanglement entropy. The third model introduces the first string theory embedding of hierarchical FQHEs, using IIA string on C^2/Z_n.
Recently, the semiclassical theory of the anomalous Hall effect induced by the Berry curvature in Bloch bands has been introduced. The theory operates only with gauge invariant concepts, that have a simple semiclassical interpretation and provides a clear distinction among various contributions to the Hall current. While the construction of such an approach to the anomalous Hall effect problem has been long sought, only the new semiclassical theory demonstrated the agreement with quantitative results of rigorous approaches based on the Green function techniques. The purpose of this work is to review the semiclassical approach including the early ideas and the recent achievements.
This is a reply to the comment by O. Narikiyo (cond-mat/0012505) on our paper J. Phys. Soc. Jpn. {\bf 68}, (1999) 1614. We point out mistakes about his arguments, and we show that our analysis is compatible with the established Fermi liquid theory, so the obtained result is justified.
We continue the program started in cond-mat/9809384 and explain the statistics of the excitations for the generalizations of the paired states in the quantum Hall effect in terms of the parafermion statistics. We show that these excitations behave as combinations of bosons and parafermions. That generalizes the prior treatment of the paired (Pfaffian) state where the excitations behave as combinations of bosons and fermions. We explain what it means, from a quantum mechanical point of view, for a particle to be a `parafermion' rather than a boson or a fermion and work through several explicit examples. The resulting multiplets coincide exactly with the angular momentum multiplets found numerically for the $k+1$ particle interaction Hamiltonian on a sphere. We also present a proof that the wave functions found in cond-mat/9809384 are indeed the correlation functions of the parafermion conformal field theory.
We study the transport properties of pinned striped quantum Hall phases. We show that, under quite general assumptions, the macroscopic conductivity tensor satisfies a semicircle law. In particular, this result is valid for both smectic and nematic stripe phases, independent of the presence of topological and orientational defects such as dislocations and grain boundaries. As a special case, our results explain the experimental validity of a product rule for the dissipative part of the resistivity tensor, which was previously derived by MacDonald and Fisher (cond-mat/9907278) for a perfect stripe structure.
The symmetry properties of the resistance of mesoscopic samples in the quantum Hall regime are investigated. In addition to the reciprocity relation, our samples obey new symmetries, that relate resistances measured with different contact configurations. Different kinds of symmetries are identified, depending on whether the magnetic field value is such that the system is above, or below, a quantum Hall transition. Related symmetries have recently been reported for macroscopic samples in the quantum Hall regime by Ponomarenko et al. [Solid State Commun. 130, 705 (2004)], and Karmakar et al. (preprint cond-mat∕0309694).
There has been a corporative absence of understanding of Hall anomaly data in the mixed state in terms of vortex many-body effect and pinning, because of the dominant theoretical influence. Now D'Anna et al. [ Phys. Rev. Lett. 81, 2530 (1998) (cond-mat/9808164)] are brave enough to announce the prominent role played by vortex many-body effect and pinning in their interpretation of their own data. Here I wish to point out: (1) Indeed the data of D'Anna et al. can be explained within an existing Hall anomaly theory based on vortex many-body considerations; (2) It is not surprising that their data are not consistent with available microscopic Hall anomaly theories, because those theories are mathematically incorrect; and (3) The courage of D'Anna et al. should be appreciated.
We derive a microscopic model describing low-lying edge excitations in a fractional quantum Hall liquid with v = v*/(phi v* + 1). For v* > 0, it is found that the composite-fermion model reduces to an SU(v*) Calogero-Sutherland model in a dimension reduction, whereas it is not exactly soluble for v* < 0. However, the ground states in both cases can be found, and the low-lying excitations can show chiral Luttinger-liquid behaviors. On the other hand, we show that the finite-temperature behavior of the G-T curve will deviate from the prediction of the chiral Luttinger liquid. We also point out that the suppression of the "spin'' degrees of freedom agrees with very recent experiments by Chang et al. [Phys. Rev. Lett. 77, 2538 (1996)]. The two-boson model of Lee and Wen (preprint, cond-mat/9801318) is described microscopically.
We provide details of a shorter letter and cond-mat/9702098 and some new results. We describe a Chern-Simons theory for the fractional quantum Hall states in which magnetoplasmon degrees of freedom enter. We derive correlated wavefunctions, operators for creating quasiholes and composite fermions and bosons (which are electrons bound to zeros). We show how the charge of these particles and mass gets renormalized to the final values and compute the effective mass approximately. By deriving a hamiltonian description of the composite fermions and bosons and their charge and current operators, we make precise and reconcile many notions that have been associated with them.