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1. Thermal SU(2) lattice gauge theory for intertwined orders and hole pockets in the cuprates

   https://doi.org/10.1073/pnas.2606117123  

   Pandey, Harshit; Christos, Maine; Bonetti, Pietro M; Shanker, Ravi; Sharma, Sayantan; Sachdev, Subir (May 2026, Proceedings of the National Academy of Sciences)

   The cuprate pseudogap phase displays Fermi arc spectral weight in photoemission and scanning tunneling microscopy, while recent magnetotransport observations yield evidence for the existence of hole pockets of fractional areap/8, wherepis the doping density. We present a Monte Carlo study of a thermal SU(2) lattice gauge theory which can reconcile these observations. Our simulation includes the SU(2) gauge fieldUof aπ-flux spin liquid, and a SU(2) fundamental chargeeHiggs bosonB. There is a Yukawa coupling betweenB, the fermionic spinons of the spin liquid, and the hole pockets of a fractionalized Fermi liquid. At the higher temperatures of the pseudogap, the finite-doping sign problem is evaded by including only thermal fluctuations ofBandU, while the fermions are diagonalized exactly for each boson background. Our study also yields a fractionalized description of intertwined orders at lower temperatures, including the onset ofd-wave superconductivity by the expulsion of vortices with flux $h/\left(2e\right)$ , each with charge-order halos. We discuss conditions under which quantum oscillations in the density of states from hole pockets of area $p/8$ could be observable in clean under-hole-doped cuprates. 

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2. High-magnetic-field phases in U _1-x Th _x Te ₂

   https://doi.org/10.1073/pnas.2521261122  

   Moir, Camilla M; Singleton, John; Blawat, Joanna; Lee-Wong, Eric; Deng, Yuhang; Feng, Keke; Wannamaker, Tyler; Baumbach, Ryan E; Maple, M Brian (October 2025, Proceedings of the National Academy of Sciences)

   At temperaturesTmuch lower than its superconducting critical temperatureT_c= 2.1 K, the heavy fermion superconductor UTe₂has a unique phase diagram of magnetic fieldHvs. φ and θ, anglesHis tilted from theb-axis toward thea- andc-axes, respectively, of its orthorhombic unit cell. The phase diagram contains three distinct superconducting phases: SC₁in which φ and θ extend from 0 to 90° andH≤ ~15 T; SC₂for φ ≤ ~7°, θ ≤ ~4° and ~15 T ≤H≤H_m= ~35 T, the onset of the magnetic field polarized (FP) phase, and SC_FPwhich resides entirely within the FP phase in a pocket of superconductivity extending from θ ≈ 20° to 40° and from ~40 T to above 60 T. We studied the evolution of theHvs. θ phase diagram for Th concentrations 0.005 ≤x≤ 0.047 in the U_1-xTh_xTe₂system at ~0.6 K. Within this range ofxvalues, SC₁extends over 0 ≤ θ ≤ 90° andH≤ ~10 T forx= 0.047, while SC₂is suppressed. The SC_FPand FP phases are unaffected tox= 0.02 but are completely suppressed in the regionx= 0.025 to 0.047 where the residual resistance ratioRRR~3 indicates a significant amount of disorder. These results complement recent studies of nonsuperconducting disordered UTe₂single crystals in which the SC₁and SC₂phases are absent, but the FP and so-called “orphan” SC_FPphases are retained. 

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3. Superconducting phase diagram of multilayer square-planar nickelates

   https://doi.org/10.1126/science.adp4440  

   Pan, Grace A; Segedin, Dan Ferenc; TenHuisen, Sophia_F R; Bhatt, Lopa; LaBollita, Harrison; Jiang, Abigail Y; Song, Qi; Turkiewicz, Ari B; Baykusheva, Denitsa R; Nag, Abhishek; et al (June 2026, Science)

   The discovery of superconductivity in square-planar nickelates has offered a rich materials platform to explore the origins of high-temperature superconductivity. However, experimental investigations have largely been limited to the infinite-layerRNiO₂(R, rare earth) nickelates. We constructed a phase diagram of multilayer square-planar Nd_n+1Ni_nO_2n+2compounds and found signatures of superconductivity for dimensionalityn= 4 to 8. Upon decreasingn, the superconducting anisotropy evolves owing to 4felectron effects, and electronic structure characteristics approach cuprate-like behavior. Magnetic fluctuations persist from within the superconducting regime and into the overdoped, nonsuperconducting regime. The superconducting regime overlaps with that of chemically doped infinite-layer nickelates, demonstrating underlying commonalities as well as differences across varying structural realizations of square-planar nickelates. Our work establishes this layered template for creating new nickel-based superconductors. 

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4. Gigahertz multimode vibrations in graphene and MoS ₂ nanomechanical resonators at room temperature

   https://doi.org/10.1126/sciadv.ads5668  

   Jia, Hao; Ye, Fan; Feng, Philip X-L (February 2026, Science Advances)

   Probing and understanding ultrahigh-frequency/gigahertz (UHF/GHz) vibrations in atomic layer nanomechanical resonators holds strong promise for fundamental studies and technological applications, such as sensing, signal processing, and quantum engineering. However, accessing GHz flexural-mode resonances in such devices at room temperature has been challenging. Here, we demonstrate the first measurement of GHz flexural vibrations in graphene and molybdenum disulfide (MoS₂) resonators at room temperature, achieving multimode resonances (f_m,n) up to ~1.09 GHz and quality factors (Q_m,n) up to ~5400 in multilayer MoS₂resonators, andf_m,nup to ~1.03 GHz with highQ_m,n ~4500 in few-layer graphene resonators. Bothfs andQs are the highest among reported atomic layer nanomechanical resonators at room temperature, yieldingf_m,n × Q_m,n ~ 5 × 10¹²Hz. We also reveal aQscaling law with higher modes, which favors detecting GHz resonances. This study will enable exploiting multiple modes in atomic layer resonators toward resonant sensing and transduction functions at UHF/GHz. 

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5. Evidence for field induced quantum spin liquid behavior in a spin-1/2 honeycomb magnet

   https://doi.org/10.59717/j.xinn-mater.2024.100082  

   Lin, Gaoting; Shu, Mingfang; Zhao, Qirong; Li, Gang; Ma, Yinina; Jiao, Jinlong; Li, Yuting; Duan, Guijing; Huang, Qing; Sheng, Jieming; et al (January 2024, The Innovation Materials)

   One of the most important issues in modern condensed matter physics is the realization of fractionalized excitations, such as the Majorana excitations in the Kitaev quantum spin liquid. To this aim, the 3d-based Kitaev material Na₂Co₂TeO₆ is a promising candidate whose magnetic phase diagram of B // a* contains a field-induced intermediate magnetically disordered phase within 7.5 T < |B| < 10 T. The experimental observations, including the restoration of the crystalline point group symmetry in the angle-dependent torque and the coexisting magnon excitations and spinon-continuum in the inelastic neutron scattering spectrum, provide strong evidence that this disordered phase is a field induced quantum spin liquid with partially polarized spins. Our variational Monte Carlo simulation with the effective K-J₁-Γ-Γ'-J₃ model reproduces the experimental data and further supports this conclusion. 

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