† These authors contributed equally to this work. Electrical manipulation of emergent phenomena due to nontrivial band topology is a key to realize next-generation technology using topological protection. A Weyl semimetal is a three-dimensional gapless system that hosts Weyl fermions as low-energy quasiparticles 1-4 . It exhibits various exotic phenomena such as large anomalous Hall effect (AHE) and chiral anomaly, which have robust properties due to the topologically protected Weyl nodes 1-23 . To manipulate such phenomena, the magnetic version of Weyl semimetals would be useful as a magnetic texture may provide a handle for controlling the locations of Weyl nodes in the Brillouin zone. Moreover, given the prospects of antiferromagnetic (AF) spintronics for realizing high-density devices with ultrafast operation 24-26 , it would 2 be ideal if one could electrically manipulate an AF Weyl metal. However, no report has appeared on the electrical manipulation of a Weyl metal. Here we demonstrate the electrical switching of a topological AF state and its detection by AHE at room temperature. In particular, we employ a polycrystalline thin film 27 of the AF Weyl metal Mn3Sn 10,13,15,28 , which exhibits zero-field AHE. Using the bilayer device of Mn3Sn and nonmagnetic metals (NMs), we find that an electrical current density of ~10 10 -10 11 A/m 2 in NMs induces the magnetic switching with a large change in Hall voltage, and besides, the current polarity along a bias field and the sign of the spin Hall angle θSH of NMs [Pt (θSH > 0) 29 , Cu(θSH ~ 0), W (θSH < 0) 30 ] determines the sign of the Hall voltage. Notably, the electrical switching in the antiferromagnet is made using the same protocol as the one used for ferromagnetic metals 31,32 . Our observation may well lead to another leap in science and technology for topological magnetism and AF spintronics 33 . Recent extensive studies in condensed matter physics have led to the discoveries of novel quantum phases with nontrivial topology in the electronic band structure 4,34,35 . One example of such topological systems is a Weyl semimetal 1-4 . Two non-degenerate bands linearly touch at a pair of momentum points, forming gapless Weyl fermions with different chiralities in a timereversal-symmetry (TRS) or inversion-symmetry breaking state. These touching points or Weyl nodes act as topologically protected, unit-strength (anti)monopoles of underlying Berry curvature, and lead to various emergent phenomena such as large AHE, anomalous Nernst effect (ANE), chiral anomaly and optical gyrotropy 1-23 .For developing science and technology utilizing novel topological states, a crucial next step would be to manipulate these emergent phenomena electrically. In a Weyl semimetal, the manipulation can be made by moving the Weyl points around in the Brillouin zone. For this purpose, the TRS breaking or magnetic Weyl semimetals are suitable as their magnetic texture 3 may provide a handle for the manipulation. Besides, antiferromagnets (AFMs) have recently attracted significant atte...

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Magnetic skyrmions were thought to be stabilised only in inversion-symmetry breaking structures, but skyrmion lattices were recently discovered in inversion symmetric Gd-based compounds, spurring questions of the stabilisation mechanism. A natural consequence of a recent theoretical proposal, a coupling between itinerant electrons and localised magnetic moments, is that the skyrmions are amenable to detection using even non-magnetic probes such as spectroscopic-imaging scanning tunnelling microscopy (SI-STM). Here SI-STM observations of GdRu2Si2 reveal patterns in the local density of states that indeed vary with the underlying magnetic structures. These patterns are qualitatively reproduced by model calculations which assume exchange coupling between itinerant electrons and localised moments. These findings provide a clue to understand the skyrmion formation mechanism in GdRu2Si2.

Bardeen-Cooper-Schrieffer (BCS) superfluidity and Bose-Einstein condensation (BEC) are the two extreme limits of the ground state of the paired fermion systems. We report crossover behavior from the BCS limit to the BEC limit realized by varying carrier density in a two-dimensional (2D) superconductor, electron-doped layered material ZrNCl. The phase diagram, established by simultaneous measurements of resistivity and tunneling spectra under ionic gating, demonstrates a pseudogap phase in the low doping regime. The ratio of the superconducting transition temperature and Fermi temperature in the low carrier density limit is consistent with the theoretical upper bound expected in the BCS-BEC crossover regime. These results indicate that the gate-doped semiconductor provides an ideal platform for the 2D BCS-BEC crossover without added complexities present in other solid-state systems.

We propose a systematic method to generate a complete orthonormal basis set of multipole expansion for magnetic structures in arbitrary crystal structure. The key idea is the introduction of a virtual atomic cluster of a target crystal, on which we can clearly define the magnetic configurations corresponding to symmetry-adapted multipole moments. The magnetic configurations are then mapped onto the crystal so as to preserve the magnetic point group of the multipole moments, leading to the magnetic structures classified according to the irreducible representations of crystallographic point group. We apply the present scheme to pyrhochlore and hexagonal ABO3 crystal structures, and demonstrate that the multipole expansion is useful to investigate the macroscopic responses of antiferromagnets.

A heavy-fermion superconductor UPt3 is a unique spin-triplet superconductor with multiple superconducting phases. Here we provide the first report on the first-principles analysis of the microscopic superconducting gap structure. We find that the promising gap structure is an unprecedented E2u state, which is completely different from the previous phenomenological E2u models. Our obtained E2u state has in-plane twofold vertical line nodes on small Fermi surfaces and point nodes with linear dispersion on a large Fermi surface. These peculiar features cannot be explained in the conventional spin 1/2 representation, but is described by the group-theoretical representation of the Cooper pairs in the total angular momentum j = 5/2 space. Our findings shed new light on the long-standing problems in the superconductivity of UPt3.PACS numbers: 74.20.Mn, 74.20.Pq, 74.20.Rp,74.70.Tx Identifying the pairing state and the pairing mechanism is one of the most interesting and important issues in the field of unconventional superconductivity. In particular, a spin-triplet type of pairing state attracts much attention, since there are few examples except for the superfluid helium 3. In the strongly correlated electron systems, the heavy-fermion superconductor UPt 3 is one of the rare candidates for spin-triplet superconductors [1,2]. The most impressive feature of this material is the multiple superconducting phase diagram. At zero magnetic field, there appears the superconducting double transition into the A phase at the upper critical temperature T + c ∼ 540mK, and then into the B phase at the lower T − c ∼ 490mK [3]. Moreover, the C phase appears at high field and low temperature in the H − T phase diagram [4,5]. In each phase, nodal quasiparticle excitations have been observed [6][7][8][9], and also the time-reversal symmetry breaking has been reported in B phase [10][11][12]. In spite of these prominent features, the superconducting gap structure still remains to be solved. Many scenarios have been proposed based on the phenomenological approach so far [13][14][15][16]. Among them, the most promising gap symmetry has been widely believed to be E 2u models [1,[17][18][19]. However, recent measurement of the fieldangle resolved thermal transport has detected in-plane twofold oscillations in the C phase [20]. This result is inconsistent with the proposed E 2u models, because in the group-theoretical argument, it is believed that the E 2u models do not have such in-plane twofold symmetry. Such twofold symmetry seems to be rather compatible with the E 1u models proposed in Refs. [21][22][23]. This is also supported by the following observations. A small residual thermal conductivity [24] suggests the presence of point nodes with linear dispersion in the E 1u models. The Josephson effect [25] with s-wave superconductor is compatible with E 1u planar states. Thus, recently, the * nomoto.takuya@scphys.kyoto-u.ac.jp E 1u models [21][22][23] have been revisited. This strongly promoted the field-angle resolved specific heat measur...

Risk factors for wound infection after off-pump coronary artery bypass grafting are comparable with those previously reported for conventional bypass grafting. In patients with diabetes, the use of bilateral internal thoracic arteries, even when harvested in a skeletonized fashion, is a risk factor. Thus, appropriate precautions should be taken in patients with diabetes.

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