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1. Core excitation in ⁹² Mo up to high spin

   https://doi.org/10.1088/1361-6471/ad9343  

   Malik, Vishal; Palit, R; Srivastava, P C; Dey, P; Patel, Deepak; Das, Biswajit; Negi, D; Garg, U; Raut, R; Goel, Nidhi; et al (December 2024, Journal of Physics G: Nuclear and Particle Physics)

   Abstract An in-beam gamma-ray spectroscopy study of the even–even nucleus⁹²Mo has been carried out using the³⁰Si +⁶⁵Cu,¹⁸O +⁸⁰Se reactions at beam energies of 120 and 99 MeV, respectively. Angular distribution from the oriented state ratio (R_ADO) and linear polarization (Δ_asym) measurements have fixed most of the tentatively assigned spin-parity of the high-energy levels. A large-scale shell-model calculation using the GWBXG interaction has been carried out to understand the configuration and structure of both positive and negative parity states up to the highest observed spin. The high-spin states primarily originate from the coupling of excited proton- and neutron-core structures in an almost stretched manner. The systematics of the energy required to form a neutron particle-hole pair excitation,νg_9/2→νd_5/2, is discussed. The lifetimes of a few high-spin states have been measured using the Doppler shift attenuation method. Additionally, a qualitative argument is proposed to explain the comparatively strong E1 transition feeding the 7310.9 keV level. 

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2. Multiple valence-space and core-excited band terminations in Ho and Er isotopes

   https://doi.org/10.1103/393p-ghvk  

   Paul, E S; Simpson, J; Riley, M A; Baron, J S; Hampson, P_J T; Wang, X; Aguilar, A; Appelbe, D E; Ayangeakaa, A D; Boston, A J; et al (June 2026, Physical Review C)

   High-spin structures of holmium ( $Z=67$) and erbium ( $Z=68$) isotopes are presented near mass 160, a region where collective and single-particle modes of excitation compete in the generation of angular momentum at the highest experimentally attainable spins in atomic nuclei. The level schemes of the ${}^{156,157,158}\mathrm{Ho}$isotopes have been significantly extended, reaching spins in the $40\hslash$to $55\hslash$range, through multiple experiments utilizing the Gammasphere spectrometer. In particular, several new noncollective band-terminating states are reported for these nuclei. The nature of these states, including both valence-space terminations and core-excited oblateconfigurations, is discussed in terms of proton particle-hole (p-h) excitations across the semimagic $Z=64$shell closure. Cranked-Nilsson–Strutinsky (CNS) calculations have been used to interpret the nature of these noncollective states. The corresponding terminating states in ${}^{154–159}\mathrm{Er}$are also included, providing a systematic description of band termination in this mass region. In addition, three weak rotational structures have been assigned to ${}^{157}\mathrm{Ho}$at the highest spins. These collective bands are proposed to be based on a triaxial strongly deformed nuclear shape, involving neutron p-h excitations across the $N=82$shell gap. 

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3. Odd-Parity Magnetism Driven by Antiferromagnetic Exchange

   https://doi.org/10.1103/zk69-k6b2  

   Yu, Yue; Lyngby, Magnus B; Shishidou, Tatsuya; Roig, Mercè; Kreisel, Andreas; Weinert, Michael; Andersen, Brian M; Agterberg, Daniel F (July 2025, Physical Review Letters)

   Realizing odd-parity, time-reversal-preserving, nonrelativistic spin splitting is a central goal for spintronics applications. We propose a group-theory-based microscopic framework to induce odd-parity spin splitting from coplanar antiferromagnetic (AFM) states without spin-orbit coupling (SOC). We develop phenomenological models for 421 conventional period-doubling AFM systems in nonsymmorphic space groups and construct minimal microscopic models for 119 of these. We find that these AFM states can attain three possible competing ground states. These ground states all break symmetries in addition to those broken by the usual AFM order. Specifically, they give rise to either odd-parity spin-splitting, nematic order, or scalar odd-parity order related to multiferroicity. Our microscopic theories reveal that the oddparity spin-splitting energy scale is generically large and further reveal that the scalar odd-parity order gives a nonzero Berry curvature dipole without SOC. We identify 67 materials in the Magndata database for which our theory applies. We provide density-functional theory (DFT) calculations on Fe-based materials that reveal an h-wave spin splitting consistent with our symmetry arguments and apply our microscopic model to determine the nonrelativistic Edelstein response for CeNiAsO. 

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4. Engineering parafermions in helical Luttinger liquids

   https://doi.org/10.1117/12.2595632  

   Lyanda-Geller, Yuli; Ponomarenko, Vadim; Wang, Ying; Rokhinson, Leonid (August 2021, SPIE Nanoscience + Engineering)

   Drouhin, Henri-Jean M.; Wegrowe, Jean-Eric; Razeghi, Manijeh (Ed.)

   Parafermions or Fibonacci anyons leading to universal quantum computing, require strongly interacting systems. A leading contender is the fractional quantum Hall effect, where helical channels can arise from counterpropagating chiral modes. These modes have been considered weakly interacting. However, experiments on transport in helical channels in the fractional quantum Hall effect at a 2/3 filling shows current passing through helical channels on the boundary between polarized and unpolarized quantum Hall liquids nine-fold smaller than expected. This current can increase three-fold when nuclei near the boundary are spin polarized. We develop a microscopic theory of strongly interacting helical states and show that emerging helical Luttinger liquid manifests itself as unequally populated charge, spin and neutral modes in polarized and unpolarized fractional quantum Hall liquids. We show that at strong coupling counter-propagating modes of opposite spin polarization emerge at the sample edges, providing a viable path for generating proximity topological superconductivity and parafermions. Current, calculated in strongly interacting picture is in agreement with the experimental data. 

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5. Observation of odd-parity superconductivity in UTe2

   https://doi.org/10.1073/pnas.2419734122  

   Li, Zixuan; Moir, Camilla M; McKee, Nathan J; Lee-Wong, Eric; Baumbach, Ryan E; Maple, M Brian; Liu, Ying (February 2025, Proceedings of the National Academy of Sciences)

   Symmetry properties of the order parameter are among the most fundamental characteristics of a superconductor. UTe₂, which was found to feature an exceedingly large upper critical field and striking reentrant behavior at low temperatures, is widely believed to possess a spin-triplet pairing symmetry. However, unambiguous evidence for such a pairing symmetry is still lacking, especially at zero and low magnetic fields. The presence of an inversion crystalline symmetry in UTe₂requires that, if it is indeed a spin-triplet superconductor, the order parameter must be of odd parity. We report here phase-sensitive measurements of the symmetry of the orbital part of the order parameter using the Josephson effect. The selection rule in the orientation dependence of the Josephson coupling between In, ans-wave superconductor, and UTe₂suggests strongly that UTe₂possesses the odd-parity pairing state of B₁usymmetry near zero magnetic field, making it a spin-triplet superconductor. We also report the apparent formation of Andreev surface bound states on the (1−10) surface of UTe₂. 

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