The total Zeeman and Rashba magnetoconductances (G=G↑↑+G↑↓) in quantum wire, quantum point contact and open quantum dot, they do not naturally display spin changes (flipping and polarizations) in the line form, especially at the perturbative limit; this was only observed theoretically in the contributions (spin conductances):G↑↑andG↑↓. Here in this work, we study the possibility of directly observing the induced spin changes in the total magnetoconductance (perturbative limit), which would be an important tool for monitoring the spin in electron magnetotransport experiments. Using three-dimensional magnetoconductance,G(ϕ/ϕo,E), with locally applied Zeeman or Rashba effects (defined with an extensionL), we are able to detect spin changes directly in the total conductance, using variations ofLin conjunction with the application of a controllable impurity. Here using electrons with spin up, as incident electrons, the spin change (spin flipping) is observed whenG↑↓becomes dominant, generating Fabry-Pérot type ripples in the total conductance,G. These ripples are associated with asymmetries in the spin contributions, induced by the controllable impurity. This controllable impurity reveals spin changes (high up or down polarizations) through asymmetries detected in the induced ripples. Theϕ/ϕonumber of flux quanta in the limit studied here is used only to couple to the spin change generator and also to make the signatures better defined. The signatures studied here are also observed forϕ/ϕo=0.

Antiferromagnetic (AFM) materials provide a platform to couple altermagnetic (AM) spin-splitting with the magneto-optical Kerr effect (MOKE), offering potential for next-generation quantum technologies. In this work, first-principles calculations, symmetry analysis, and k·p modeling are employed to show that interlayer sliding in AFM multiferroic bilayers enables control of electronic, magnetic, and magneto-optical properties. This study reveals an intriguing dimension-driven AM crossover: the 2D paraelectric (PE) bilayer exhibits spin-degenerate bands protected by the spin-space symmetry, whereas the 3D counterpart manifests AM spin-splitting along kz ≠ 0 paths. Furthermore, interlayer sliding breaks this symmetry and stabilizes a ferroelectric (FE) state with compensated ferrimagnetism, where the Zeeman-like field is responsible for the nonrelativistic spin-splitting. In the FE phase, spin-orbit coupling (SOC) lifts accidental degeneracies and produces "alternating" spin-polarized bands through the interplay of Zeeman and Rashba effects. Crucially, spin polarization, ferrovalley polarization (ΔEV), and the Kerr angle (θk) can all be reversed by switching either sliding ferroelectricity or the Néel vector. Our findings reveal the rich coupling among electronic, magnetic, and optical orders in sliding multiferroics, illustrating new prospects for ultralow-power spintronic and optoelectronic devices.

Abstract We measure and analyze noise-induced energy-fluctuations of spin qubits defined in quantum dots made of isotopically natural silicon. Combining Ramsey, time-correlation of single-shot measurements, and CPMG experiments, we cover the qubit noise power spectrum over a frequency range of nine orders of magnitude without any gaps. We find that the low-frequency noise spectrum is similar across three different devices suggesting that it is dominated by the hyperfine coupling to nuclei. The effects of charge noise are smaller, but not negligible, and are device dependent as confirmed from the noise cross-correlations. We also observe differences to spectra reported in GaAs [Phys. Rev. Lett. 118, 177702 (2017), Phys. Rev. Lett. 101, 236803 (2008)], which we attribute to the presence of the valley degree of freedom in silicon. Finally, we observe $${T}_{2}^{* }$$ T 2 * to increase upon increasing the external magnetic field, which we speculate is due to the increasing field gradient of the micromagnet suppressing nuclear spin diffusion.

Abstract We propose a new scheme for realizing Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) Cooper pairing states within flat bands, in contrast to the conventional paradigm such as the Zeeman effect. Central to our scheme is the concept of “quantum geometric discrepancy” (QGD) that measures differences in the quantum geometry of paired electrons and drives the flat-band FFLO instability. Remarkably, we find that this instability is directly related to a quantum geometric quantity known as “anomalous quantum distance”, which formally captures QGD. To model both QGD and the anomalous quantum distance, we examine a flat-band electronic Hamiltonian with tunable spin-dependent quantum metrics. Utilizing the band-projection method, we analyze the QGD-induced FFLO instability from pairing susceptibility. Furthermore, we perform mean-field numerical simulations to obtain the phase diagram of the BCS-FFLO transition, which aligns well with our analytical results. Our work demonstrates that QGD offers a general and distinctive mechanism for stabilizing the flat-band FFLO phase.

We present the structural and magnetic properties of the pyrochlore oxide Gd2Hf2O7 using x-ray diffraction, Raman spectroscopy, magnetization, AC susceptibility, and heat capacity measurements. Gd2Hf2O7 forms in a well-ordered cubic pyrochlore phase and exhibits the characteristic Raman-active modes, indicative of the stable local coordination. AC susceptibility measurements uncover a field-induced anomaly near 15 K, which is frequency-independent and shifts linearly with field, suggesting the presence of slow spin dynamics influenced by Zeeman splitting. Heat capacity data under applied fields reveal a Schottky-like anomaly that is well described by a multilevel Schottky model, consistent with crystal field splitting of the Gd3+ levels. These results point toward a cooperative spin response arising from the interplay of weak single-ion anisotropy and geometric frustration, positioning Gd2Hf2O7 as a model system for exploring field-tunable spin correlations in low-anisotropy pyrochlores.

The photocatalytic conversion of CO2 into the renewable fuels is a promising strategy to address energy and environmental challenges, however, its limited application is mainly attributed to the inefficient charge separation and lack of active sites in conventional catalysts. Here, a spin-polarization strategy using Co2⁺ doping in lead-free perovskite Cs3Bi2Br9 (CBB) synergized with an external magnetic field (MF), is reported to achieve highly efficient CO2 reduction. The optimized Co-doped CBB (0.2CBB) exhibited a 2.6-fold enhancement in CO production rate (35.04µmolg-1h-1) compared to the pristine CBB, with further improvement to 86.56µmolg-1h-1 under 200 mT MF. Advanced characterizations together with the density functional theory calculations further revealed that the Co doping introduces spin-polarized electrons, suppresses charge recombination, and elongates the carrier lifetime (6.68ns vs 5.20ns in CBB). The Zeeman effect under MF activates the additional spin-polarized carriers, while the Co sites lower the energy barrier for *COOH intermediate formation (ΔG=-0.59 vs -0.38eV in CBB), as confirmed by the in situ FT-IR and Gibbs free energy analysis. This work pioneers the integration of spin manipulation and MF-assisted catalysis in perovskites, offering a novel pathway for the design of high-performance photocatalytic systems.

Excitons in Transition Metal Dichalcogenides (TMDs) acquire a spin-like quantum number, a pseudospin, originating from the crystal’s discrete rotational symmetry. Here, we break this symmetry using a tunable uniaxial strain, effectively generating a pseudomagnetic field acting on exciton valley degree of freedom. Under this field, we demonstrate pseudospin analogs of spintronic phenomena such as the Zeeman effect and Larmor precession and determine fundamental timescales for pseudospin dynamics in TMDs. Finally, we uncover the bosonic – as opposed to fermionic – nature of many-body excitonic species using the pseudomagnetic equivalent of the g-factor spectroscopy. Our work is the first step toward establishing this spectroscopy as a universal method for probing correlated many-body states and realizing pseudospin analogs of spintronic devices.

The orbital angular momentum (OAM) of light opens up a new physical dimension for studying light–matter interactions. In this paper, we revealed that the Zeeman splitting of plasmonic resonances in a magnetoplasmonic particle under OAM beams is induced by only a transverse magnetic field, breaking the preconception that Zeeman splitting of plasmonic resonances under non-OAM sources is induced by a longitudinal magnetic field. Zeeman splitting of plasmonic scattering resonances occurs under circularly polarized light carrying OAM, while no Zeeman splitting is observed in magnetoplasmonic particles under circularly polarized light carrying no OAM. These anomalous phenomena are the result of the longitudinal dipole excited by OAM. We also demonstrate tunable rotation of longitudinal dipolar radiation patterns by an external magnetic field. The reported research on magnetoplasmon behavior with OAM would provide great potential to control electromagnetic waves and add additional degrees of freedom to the spectroscopies.

An analog of nuclear magnetic resonance is realized in a microwave network with symplectic symmetry. The network consists of two identical subgraphs coupled by a pair of bonds with a length difference corresponding to a phase difference of π for the waves traveling through the bonds. As a consequence, all eigenvalues appear as Kramers doublets. Detuning the length difference from the π condition Kramers degeneracy is lifted, which may be interpreted as a Zeeman splitting of a spin 1/2 in a magnetic field. The lengths of another pair of bonds are modulated periodically with frequencies of some 10MHz by means of diodes, thus emulating a magnetic radio-frequency field. This setup enables the realization of well-known NMR phenomena, such as the transformation from the laboratory to the rotating frame and the observation of Lorentzian-shaped resonance lines.

Topological materials have gained significant attention due to their unique electronic properties, making them promising candidates for future electronics and quantum devices. Two single-crystalline CoP3 samples were synthesized by chemical vapor transport with different process steps and characterized in this study. At low temperatures, both samples demonstrated giant magnetoresistance, Shubnikov–de Haas oscillations, negative magnetoresistance (NMR), and weak antilocalization (WAL), with sample 2 also showing Zeeman splitting. The difference between the two samples mainly arises from the varying hole concentrations caused by different P vacancies, which result in the Fermi level of sample 2 being closer to the quadratic contact point of the band structure. The observation of giant magnetoresistance, Shubnikov–de Haas oscillations, negative magnetoresistance, and weak antilocalization provides experimental evidence for CoP3 as a potential topological material. This work provides valuable insights into the fundamental transport mechanisms at low temperatures, suggesting that CoP3 could hold potential for applications in spintronic devices and quantum computing.

Abstract We assess the thermal resilience of key quantum resources-( ℓ 1 {\ell }_{1} )-norm coherence ( Q Q ), quantum discord ( D D ), logarithmic negativity ( ℒN {\mathcal{ {\mathcal L} N}} ), Bell nonlocality ( ℬ {\mathcal{ {\mathcal B} }} ), and quantum steering ( S {\mathcal{S}} )-in a bipartite Lipkin–Meshkov–Glick (LMG) spin system subject to competing Dzyaloshinskii–Moriya (DM) interactions and Zeeman splitting. By varying temperature ( T T ), spin–spin coupling ( λ \lambda ), magnetic field strength ( B 0 {B}_{0} ), and DM amplitude ( D z {D}_{z} ), we reveal a clear hierarchy of thermal stability: coherence and discord remain robust well beyond the temperatures at which nonlocality ( ℬ {\mathcal{ {\mathcal B} }} ), steering ( S {\mathcal{S}} ), and bipartite entanglement ( ℒN {\mathcal{ {\mathcal L} N}} ) undergo successive thermal collapse. Stronger spin–spin coupling λ \lambda and nonzero DM strength D z ≥ 0 {D}_{z}\ge 0 not only amplify overall quantum correlations but also elevate the critical temperatures T c {T}_{c} for the survival of each resource. In contrast, a large B 0 {B}_{0} polarizes the spins into paramagnetic states, thereby suppressing all quantum features at fixed T T . Notably, high amplitude of DM interactions preserves residual coherence and discord even in the high-temperature limit ( T ≫ T c ) \left(T\gg {T}_{c}) . These results establish practical operating thresholds for LMG-based quantum technologies in thermal environments and highlight D z {D}_{z} as a powerful tuning parameter for engineering thermally robust quantum resources.

We study the electronic spin Zeeman effect for an effective spin-1/2-system subject to both strong coupling to a low-frequency optical cavity and an external static magnetic field. In particular, we address the interplay between the cavity magnetic field component in a cavity Zeeman interaction and the canonical spin Zeeman interaction from the perspective of an effective spin-polariton Hamiltonian. The latter is derived from the minimal coupling Pauli-Fierz Hamiltonian beyond the common dipole approximation via first-order quasi-degenerate perturbation theory. We find the spin Zeeman effect to be modified in the presence of the cavity field due to the formation of spin-polariton states, which result from an intricate interplay of cavity and external magnetic fields in our model. Spin-polariton signatures are discussed in the context of electron paramagnetic resonance spectroscopy along with cavity-induced modifications of the electronic g-factor.

The polarization of the Ca ii resonant doublet (H and K lines) and subordinate infrared triplet lines are valuable observables for diagnosing the magnetism of the solar chromosphere. It is thus necessary to understand in detail the physical mechanisms that play a role in producing their Stokes profiles in the presence of magnetic fields. We use the spectral synthesis module of the HanleRT-TIC code to study the impact of anisotropic radiation pumping with partial frequency redistribution (PRD) and J-state interference (JSI), considering a plane-parallel semi-empirical static solar atmospheric model. We also study the sensitivity of the lines to magnetic fields of various strengths and orientations accounting for the joint action of the Hanle and Zeeman effects. Taking PRD into account is required to suitably model the polarization in the core regions of the resonant lines, whereas JSI plays a crucial role in their far wings. We confirm that the metastable lower levels of the subordinate lines also contribute to the scattering polarization of the K line. In the presence of horizontal magnetic fields, we find that the resonant lines are sensitive to a wide range of field strengths (sub-gauss to tens of gauss), whereas the scattering polarization of the infrared triplet lines are mainly sensitive to milligauss field strengths. At a near-limb line of sight (LOS) with μ = 0.1, the Hanle effect modifies the scattering polarization via a depolarization and a rotation in the plane of linear polarization. At disk center, horizontal fields in the 1D semi-empirical model give rise to linear polarization signals; in the K line, this is governed by the Hanle effect in the sub-gauss to few tens of gauss range and by the Zeeman effect in stronger fields. For vertical magnetic fields, the Hanle effect does not operate, but the linear polarization wings of the resonance lines are sensitive to magneto-optical effects. Finally, we find that the atomic level polarization exerts an influence on the outer circular polarization lobes of the the resonant lines and that the weak field approximation tends to overestimate the LOS magnetic field component if this frequency range is considered.

Metal halide perovskites are rapidly emerging as a promising platform for spin-polarized lasers. However, the weak Zeeman effect of perovskites makes it challenging to realize the magnetic-field induction and manipulation of spin-polarized lasing. Here we introduce a ferromagnetic spin filtering effect in perovskites to achieve spin-polarized lasing. A composite is designed by incorporating ferromagnetic Fe3O4 nanoparticles into an organic-inorganic hybrid perovskite. Under a magnetic field, the Fe3O4 nanoparticle selectively captures electrons with particular spin from the perovskite, resulting in an effective spin polarization for lasing. The magnetic field direction and strength determine the chirality and circular polarization degree of the spin-polarized perovskite lasing. Furthermore, wavelength-tunable spin-polarized lasers are realized by exploiting the composition-tailored bandgaps of hybrid perovskites. Our work establishes a ferromagnetic spin filtering strategy for spin-polarized perovskite lasers.

SummaryCombining the effective-mass theory with valence-band anticrossing model, we investigate the electronic structures and Zeeman splitting characteristics of dilute bismuth GaAs nanowires under axial magnetic fields. Calculated results demonstrate that absorption spectra of GaAs1-xBix nanowires exhibit a linear relationship of Zeeman splitting energy with magnetic field regardless of the diameter and Bi composition, due to lifting of degeneracy in both electron and hole states. Importantly, we find that enhanced Zeeman splitting energies and effective g factors of GaAs1-xBix nanowires with larger diameters and lower Bi concentrations can be obtained, which principally arises from splitting energy of the hole states involved in first peaks of σ+ and σ− spectra. Further, normalized magnetic circular dichroism spectra corroborate the Zeeman splitting features observed in the absorption spectra. Our research manifests that GaAs1-xBix nanowires exhibit promising potential for quantum information processing applications because of their large and tunable effective g factors.

Two-dimensional transition metal dichalcogenides possess remarkable excitonic properties, including strong Coulomb interactions, valley-selective optical transitions, and high photoluminescence efficiency. Among them, localized excitons with ultra-narrow linewidths, extended coherence times, and pronounced sensitivity to external perturbations are emerging as promising candidates for quantum optics and optoelectronics. However, their observation and application at room temperature remain limited due to rapid exciton thermalization. Here, we demonstrate the formation of stable localized excitons at room temperature by vertically stacking monolayer WSe2 onto gold nanorods. This hybrid system leverages both localized strain and plasmonic resonance to generate plasmon-hybridized localized excitons. These excitons exhibit reversed Zeeman splitting and magnetic-field-dependent linear polarization, in contrast to their uncoupled counterparts. First-principles calculations combined with finite element method (FEM) simulations reveal the underlying mechanism of exciton localization driven by the interplay between strain and plasmonic confinement. Our findings provide fundamental insights into exciton–plasmon coupling in two-dimensional systems and establish pathways for designing high-performance excitonic devices that operate at room temperature.

A Berry phase of odd multiples of π inferred from quantum oscillations (QOs) has often been treated as evidence for nontrivial reciprocal space topology. However, disentangling the Berry phase values from the Zeeman effect and the orbital magnetic moment is often challenging. In centrosymmetric compounds, the case is simpler as the orbital magnetic moment contribution is negligible. Although the Zeeman effect can be significant, it is usually overlooked in most studies of QOs in centrosymmetric compounds. Here, we present a detailed study on the nonmagnetic centrosymmetric SrGa2 and BaGa2, which are predicted to be Dirac nodal line semimetals based on density functional theory (DFT) calculations. Evidence of the nontrivial topology is found in magnetotransport measurements. The Fermi surface topology and band structure are carefully studied through a combination of angle-dependent QOs, angle-resolved photoemission spectroscopy (ARPES), and DFT calculations, where the nodal line is observed in the vicinity of the Fermi level. Strong de Haas–van Alphen fundamental oscillations associated with higher harmonics are observed in both compounds, which are well fitted by the Lifshitz-Kosevich (LK) formula. However, even with the inclusion of higher harmonics in the fitting, we found that the Berry phases cannot be unambiguously determined when the Zeeman effect is included. We revisit the LK formula and analyze the phenomena and outcomes that were associated with the Zeeman effect in previous studies. Our experimental results confirm that SrGa2 and BaGa2 are Dirac nodal line semimetals. Additionally, we highlight the often overlooked role of spin-damping terms in Berry phase analysis.

Magnetic proximity effects (MPE) in transition-metal dichalcogenide (TMD)-magnet heterostructures can tailor valley properties, enabling spintronic, valleytronic, and quantum functionalities. The MPE, however, is strongly influenced by the magnetic phase of the adjacent material, and active control over this phase-dependent coupling remains elusive. Here, we demonstrate layer-number-driven modulation of the MPE in air-stable CrPS4/WSe2 heterostructures. The valley polarization, Zeeman splitting, and in-plane optical anisotropy are dictated by the odd-even layer number of CrPS4: even-layer CrPS4 induces an antiferromagnetic proximity effect, yielding nearly unchanged valley polarization and an S-shaped Zeeman splitting, whereas odd-layer CrPS4 produces a ferromagnetic proximity effect, enhancing valley polarization and generating a Z-shaped Zeeman splitting. Under an external magnetic field, the Raman polarization of WSe2 and CrPS4 evolves synchronously via magnon-phonon coupling. Increasing the CrPS4 thickness suppresses interfacial charge inhomogeneity, thereby strengthening the thickness-dependent anisotropic optical response. These results uncover a direct connection between magnetic dimensionality and excitonic behavior, offering a versatile strategy for engineering valleytronic and anisotropic optical functionalities in two-dimensional quantum materials.

Abstract Planar graphene-NbSe 2 Josephson junctions can support supercurrents at high in-plane magnetic fields ( B ∥ ) due to the robust superconductivity in thin NbSe 2 , protected from both orbital and spin-driven decay by a combination of atomic thickness and Ising spin orbit coupling. We fabricate and characterize a clean, flat graphene-NbSe 2 junction encapsulated in hBN. The junction is ballistic, exhibiting Fabry–Pérot oscillations of the critical current, and supports very high critical current densities. The junction is remarkably robust to both in-plane and out-of-plane magnetic fields, and exhibits a clear ballistic Josephson effect up to the maximally available in-plane field of 8 T. We model the suppression of the critical current using a tight-binding model, accounting for the large overlap area between the NbSe 2 and graphene. We find that the suppression is governed by both the Zeeman splitting of Andreev bound states and by the flux threading the van-der-Waals gap that separates graphene from the NbSe 2 leads.

Abstract We theoretically investigated a Zeeman-type spin-polarizer, which utilizes the Zeeman effect to generate spin-polarized current. The device consists of an InAs one-dimensional electron gas channel, a ferromagnetic (FM) nanomagnet, and a nanoscale gate electrode. Applying gate voltages independently to the FM nanomagnet and the gate electrode creates spin-dependent tunneling barriers. Our calculations demonstrate that reducing the dimensionality of the channel and introducing a spin-dependent quantum well and a single tunneling barrier significantly enhances the thermal stability of the spin-polarizer. Furthermore, we find spin-polarization exceeding 30 % in magnitude at 5.0 K , which represents a substantial improvement over previous reports. These findings provide a promising pathway toward the realization of high-performance, thermally stable Zeeman-type spin-polarizer for future spintronic applications.