CNM - Publication Highlights

Organic photovoltaics (OPVs) offer a promising solution for indoor energy harvesting. However, fundamental investigations to understand and optimize industrial processes such as roll-to-roll lamination for upscaling remain limited. This study investigates a critical failure mode in the upscaling of OPVs. 

One major challenge ...

Altermagnets are collinear compensated magnets in which the magnetic sublattices are related by rotation rather than translation or inversion. One of the quintessential properties of altermagnets is the presence of split chiral magnon modes. Recently, such modes have been predicted in MnF₂. 

Here, we report inelastic neutron scattering results ...

High-pressure studies reveal a stark contrast between the superconducting properties of double-layer Ruddlesden-Popper (RP) nickelates La₂⁢PrNi₂⁢O₇ and La₃⁢Ni₂⁢O₇. While La₂⁢PrNi₂⁢O₇ exhibits bulk superconductivity, La₃⁢Ni₂⁢O₇ displays filamentary behavior, suggesting that superconductivity is confined to phase interfaces rather than the bulk. Since magnetism emerges ...

Exchange interactions are mediated via orbital overlaps across chemical bonds. Thus, modifying the bond angles by physical pressure or strain can tune the relative strength of competing interactions. Here we present a remarkable case of such tuning between the Heisenberg (J) and Kitaev (K) exchange, which respectively establish magnetically ordered and spin liquid phases on a honeycomb lattice. We observe ...

The pursuit of a unifying theory for non-BCS superconductivity has faced significant challenges. One approach to overcome such challenges is to perform systematic investigations into superconductors containing d-electron metals in order to elucidate their underlying mechanisms. Recently, the Sc₆MTe₂ (M = d-electron metal) family has emerged as a unique series of isostructural compounds exhibiting superconductivity across a range of 3d, 4d, and 5d electron systems. 

In this study, muon spin rotation, neutron diffraction, and magnetization techniques are employed to probe ...

Layer-by-layer (LBL) deposition has become a facile and promising method to fabricate highly efficient organic solar cells (OSCs). However, characterization and optimization of 3D morphology remain a grand challenge for LBL- processed active layers, and their correlation with photovoltaic properties of OSC devices is not clear to date. 

Here, to address this issue, ...

Kagome metals with van Hove singularities near the Fermi level can host intriguing quantum phenomena such as chiral loop currents, electronic nematicity, and unconventional superconductivity. However, to our best knowledge, unconventional magnetic states driven by van Hove singularities–like spin-density waves–have not been observed experimentally in kagome metals. Here, we report ...

There are substantial changes in soil structure in regions where the soil is freezing. Water movements in the freezing soil introduce level changes beyond what can be expected by the expansion of water when it freezes. The impact of frost heave is seasonal damage to our built environment ...

The interplay between topology and superconductivity generated great interest in condensed matter physics. Here, we unveil an unconventional two-dimensional superconducting state in the Dirac nodal line semimetal ZrAs₂ which is exclusively con ned to the top and bottom surfaces within the crystal’s ab plane. 

As a remarkable consequence ...

Crystalline solids can become band insulators due to fully lled bands, or Mott insulators due to strong electronic correlations. While Mott insulators can theoretically occur in systems with an even number of electrons per unit cell, distinguishing them from band insulators experimentally has remained a longstanding challenge. 

In this work, we present ...

The topological nature of the electronic bands or spin structure has direct manifestation in experimentally measured Hall conductivity. The extra topological (or geometrical) component to the Hall effect (THE) usually emerges due to multi-k structures, which inherently possess a finite static scalar spin chirality (SSC). Generating a THE in a single-k structure necessitates the consideration of the dynamical  origin of SSC, the real material examples of such cases remain scarce to date.

Magnetically intercalated transition metal dichalcogenides (TMDs) provide a versatile three-dimensional (3D) material platform to explore quantum phenomena and functionalities that emerge from an intricate interplay among magnetism, band structure, and electronic correlations. 

The Airy wave packet is a solution to the potential-free Schrödinger equation that exhibits remarkable properties such as self-acceleration, nondiffraction, and self-healing. Although Airy beams are now routinely realized ....

Two-dimensional (2D) kagome lattice metals are interesting because their corner sharing triangle structure enables a wide array of electronic and magnetic phenomena. Recently, post-growth annealing is shown to both suppress charge density wave (CDW) order and establish long-range CDW with the ability to cycle between states repeatedly in the kagome antiferromagnet FeGe. 

Here we perform ...

The anomalous Hall effect (AHE) has emerged as a key indicator of time-reversal symmetry breaking (TRSB) and topological features in electronic band structures. Absent of a magnetic field, the AHE requires spontaneous TRSB but has proven hard to probe due to averaging over domains. The anomalous component of the Hall effect is thus frequently derived from extrapolating the magnetic field dependence of the Hall response. We show ....

Multiband superconductivity arises when multiple electronic bands contribute to the formation of the superconducting state, allowing distinct pairing interactions and gap structures. Here, we present field- and temperature-dependent data  ...

The spiral spin liquid (SSL) is a highly degenerate state characterized by a continuous contour or surface in reciprocal space spanned by a spiral propagation vector. Although the SSL state has been predicted in a number of various theoretical models, very few materials are so far experimentally identified to host such a state. Via combined single-crystal wide-angle and small-angle neutron scattering, we report observation  ...

Superconducting domes, ubiquitous across a variety of quantum materials, are often understood as a window in which pairing is favored, opened by the fluctuations of competing orders. Yet, the understanding of how such a window closes is missing. Here, we show that inelastic neutron scattering ...

The observation of superconductivity in La₃Ni₂O_7–δ under pressure, following the suppression of a high-temperature density wave state, has attracted considerable attention. The nature of this density wave order was not clearly identified. Here we probe the magnetic response of the zero-pressure phase of La₃Ni₂O_7–δ as hydrostatic pressure is applied, and find that the apparent single density wave transition at zero applied pressure splits into two. The comparison of our muon-spin rotation ...

Encoding information in antiferromagnetic (AFM) domains is a promising solution for the ever growing demand in magnetic storage capacity. The absence of a macroscopic magnetization avoids crosstalk between different domain states, enabling ultrahigh density spintronics while being detrimental to the domain detection and manipulation. Disentangling these merits and disadvantages seemed so far unattainable. We report evidence ...

Spin moiré superlattices (SMSs) formed by interfacing conventional electronic states with a multi-q magnetic lattice have been proposed as a magnetic analog of crystallographic moiré systems. The electron-minibands created in an SMS are expected to be enriched by the vector-field nature of the magnetic interaction and offer new types of moiré tunability, topological protection, and Berry curvature effects. However, most spin-vortex-hosting systems discovered to date have carrier mean free paths l_mfp significantly shorter than their spin-moiré lattice constant a_spin, inhibiting mini-band-formation. Furthermore ...

Skyrmions are particlelike vortices of magnetization with nontrivial topology, which are usually stabilized by Dzyaloshinskii-Moriya interactions (DMI) in noncentrosymmetric bulk materials. Exceptions are centrosymmetric Gd- and Eu-based skyrmion-lattice (SL) hosts with zero DMI, where both the SL stabilization mechanisms and magnetic ground states remain controversial. We address these here by investigating both the static and dynamical spin properties  ...

Energy-efficient, safe, and reliable Li-ion batteries (LIBs) are required for a wide range of applications. The introduction of ultra-thick graphite anodes, desired for high energy densities, meets limitations in internal electrode transport properties, leading to detrimental consequences. Yet, there is a lack of experimental tools capable of providing a complete view of local processes. Here, a multi-modal operando measurement approach is introduced, enabling quantitative spatio-temporal observations of Li concentrations and intercalation phases in ultra-thick graphite electrodes.
Neutron imaging and diffraction concurrently provide ...

The detailed anisotropic dispersion of the low-temperature, low-energy magnetic excitations of the candidate spin-triplet superconductor UTe₂ is revealed using inelastic neutron scattering. The magnetic excitations emerge from the Brillouin zone boundary at the high symmetry Y and T points and disperse along the crystallographic b-axis. In applied magnetic fields ...

Methods to prepare and characterize neutron helical waves carrying orbital angular momentum (OAM) were recently demonstrated at small-angle neutron scattering (SANS) facilities. These methods enable access to the neutron orbital degree of freedom which provides new avenues of exploration in fundamental science experiments as well as in material characterization applications. 

However, ....