Anisotropic RKKY interaction in semi-Dirac semimetals

In $d$-dimensional systems with purely linear dispersion, the Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction typically follows an isotropic decaying law $J_{iso}\propto {\rm sin}\left(2k_FR\right)/R^d$ ($1/R^{d+\zeta}$) in doped (undoped) case, where $|\omega|^{\zeta}$ denotes the density of states (DOS). However, this law is not valid in semi-Dirac semimetal (S-DSM), which is noted for its anisotropic dispersion, i.e., linear in certain axes but parabolic in the orthogonal axes. By exploring the magnetic interaction in $2$-dimensional (2D) S-DSM and two types of 3D S-DSMs, new laws are derived for the direction-dependent RKKY interaction. Compared to $J_{iso}$, the interaction here decays much more slowly with the impurity distance $R$ as impurities are deposited on the relativistic axis, while a faster decaying law is exhibited with impurities deposited on the non-relativistic axis. The former is induced by the prolonged decaying rate of the carrier propagator and the modified DOS with smaller power $\zeta$, while the latter is caused by the modification to the energy of the carrier propagator. The both are attributed to the anisotropy of the semi-Dirac dispersion. We have further discussed the case with spin-momentum locking. Some phenomena (not exist in DSMs) are highlighted, including the strong magnetic anisotropy with $XYZ$ spin model, and the creation (annihilation) of Dzyaloshinskii-Moriya (DM) terms with impurities deposited on the relativistic (non-relativistic) axis. Our work provides an alternative option to identify the anisotropic nature of semi-Dirac dispersion by measuring the RKKY interaction

Comparison of oblique and transforaminal approaches to lumbar interbody fusion for lumbar degenerative disease: An updated meta-analysis

ObjectiveOblique lumbar interbody fusion (OLIF) and transforaminal lumbar interbody fusion (TLIF) are widely used in the treatment of lumbar degenerative diseases. A meta-analysis was performed to examine the clinical and radiological effects of these two techniques.MethodsA search of relevant literature from several databases was conducted until November 2021. Perioperative outcomes, clinical and radiological results, and complications were analyzed.ResultsFifteen qualified studies were included. OLIF showed a shorter operative time and length of hospital stay and less blood loss than TLIF. Early postoperative Visual Analogue Scale for back pain were significantly lower in OLIF than in TLIF (P = 0.004). Noteworthy, although the preoperative Oswestry Disability Index (ODI) of the OLIF group was higher than that of the TLIF group (P = 0.04), the postoperative ODI was significantly lower (P < 0.05). Radiologically, the results showed that the disc and foraminal heights of OLIF were significantly higher than those of TLIF postoperatively. Moreover, OLIF can restore more segmental lordosis than TLIF in the early postoperative period. Furthermore, OLIF showed better fusion rates than TLIF (P = 0.02), with no difference in cage subsidence (13.4% vs. 16.6%). No significant differences in overall and approach-related complications between the two groups.ConclusionThe OLIF group showed an advantage in terms of operative time, hospitalization, intraoperative blood loss, early back pain relief, postoperative function recovery, disc and foraminal heights, early segmental lordosis, and fusion rate compared to TLIF. For both procedures, the incidence rates of overall and approach-related complications were comparable

SimSwap: An Efficient Framework For High Fidelity Face Swapping

We propose an efficient framework, called Simple Swap (SimSwap), aiming for generalized and high fidelity face swapping. In contrast to previous approaches that either lack the ability to generalize to arbitrary identity or fail to preserve attributes like facial expression and gaze direction, our framework is capable of transferring the identity of an arbitrary source face into an arbitrary target face while preserving the attributes of the target face. We overcome the above defects in the following two ways. First, we present the ID Injection Module (IIM) which transfers the identity information of the source face into the target face at feature level. By using this module, we extend the architecture of an identity-specific face swapping algorithm to a framework for arbitrary face swapping. Second, we propose the Weak Feature Matching Loss which efficiently helps our framework to preserve the facial attributes in an implicit way. Extensive experiments on wild faces demonstrate that our SimSwap is able to achieve competitive identity performance while preserving attributes better than previous state-of-the-art methods. The code is already available on github: https://github.com/neuralchen/SimSwap.Comment: Accepted by ACMMM 202