We propose the linear and nonlinear anomalous planar Hall effect (APHE) in tilted Weyl semimetals in the presence of an in-plane magnetic and electric field, where the field-induced Berry connection plays a key role. The conductivity of linear APHE is ascribed to the quantum metric and is antisymmetric in nature, distinct from the well-known chiral anomaly induced PHE arising from the Berry curvature. Using a tilting vector to describe the model, we demonstrate the constrains on the linear and nonlinear APHE by the tilting directions. The linear APHE is intrinsic that is determined by the topological properties of energy bands, whereas the nonlinear APHE is extrinsic. The predicted linear and nonlinear APHE are inherently different from others and may shed light on a deeper understanding on transport nature of the tilted Weyl semimetals.

Integrated photonics is a remarkable platform for scalable classical and quantum light-based information processing. However, polarization manipulation on a chip despite of its fundamental significance in information processing remains elusive. Polarization manipulation capabilities have been recently demonstrated in femtosecond laser-inscribed twisted waveguides, although the systematic theoretical description of polarization manipulation has not been established for this architecture. In this paper we develop a rigorous theory of a twisted waveguide unveiling its eigenmodes and transmission matrix in the closed form. Utilizing the developed theory, we demonstrate that twisted waveguides can realize virtually arbitrary polarization transformations while satisfying reasonable design constraints. This fact combined with low cost and ease of prototyping of laser inscribed photonic integrated circuits allows us to suggest twisted waveguide as a robust building block for on-chip polarization-encoded information processing.

Identification of the internal dynamics of multidomain proteins is crucial for clarifying the mechanism of their functions. The neutron spin echo (NSE) technique is well suited for studying internal dynamics. However, the requirement for relatively high protein concentrations and the lack of appropriate analytical methods have impeded the investigation of the internal dynamics with NSE. To overcome these difficulties, we employed a unique approach to study the internal dynamics of a multidomain protein, EcoO109I, whose dynamics was anticipated to be pertinent to DNA degradation. We anticipated a synergetic effect between the NSE measurement at interference-free protein concentration and all-atom molecular dynamics simulation. Through this approach, the internal dynamics of EcoO109I was successfully observed within temporal and spatial scales. Additionally, principal component analysis (PCA) was applied to the internal dynamics trajectory to identify the dominant motion of the internal dynamics. The first PCA mode, which was the most cooperative among all PCA modes, mainly explained the internal dynamics. This dominant mode of EcoO109I exhibited the motion which facilitated both the access of DNA to the recognition site and the cleavage of DNA. Therefore, our approach can identify the functionally relevant internal dynamics of multidomain proteins.

Laser produced $\gamma$-photons can make an important impact on applied and fundamental physics that require high $\gamma$-photon yield and strong collimation. We propose the addition of a constant magnetic field to the laser-solid interaction to obtain the aforementioned desired $\gamma$-photon properties. The $\gamma$-ray flash spatial and spectral characteristics are obtained via quantum electrodynamic particle-in-cell simulations. When the constant magnetic field aligns with the laser magnetic field, then the $\gamma$-ray emission is significantly enhanced. Moreover, the $\gamma$-photon spatial distribution becomes collimated, approximately in the form of a disk.

The acceleration theorem for wave packet propagation in periodic potentials disentangles the $k$-space dynamics and real space dynamics. This is well known and understood for Bloch oscillations and super Bloch oscillations in the presence of position-independent forces. Here, we analyze the dynamics of a model system in which the $k$-space dynamics and the real space dynamics are inextricably intertwined due to a position-dependent force provided by a parabolic trap. We demonstrate that this coupling gives rise to significantly modified and rich dynamics when the lattice is shaken by a modulated parabolic potential. The dynamics range from chirped Bloch-harmonic oscillations to asymmetric spreading oscillations. We analyze these findings by tracing the spatiotemporal dynamics in real space and by visualizing the relative phase in the $k$-space dynamics which leads to an accurate explanation of the obtained phenomena. We also compare our numerical results to a local acceleration model and obtain very good agreement for the case of coherent oscillations, however, deviations for oscillations with spreading dynamics which altogether supports the interpretations of our findings.

The optical properties of metallic nanoparticles are most often considered in terms of plasmons, the coupled states of light and quasifree electrons. Confinement of electrons inside the nanostructure leads to another, very different type of resonances. We demonstrate that these confinement-induced resonances typically join into a single composite “super-resonance,” located at significantly lower frequencies than the plasmonic resonance. This super-resonance influences the optical properties in the low-frequency range, in particular, producing giant nonlinearities. We show that such nonlinearities can be used for efficient down-conversion from optical to terahertz and midinfrared frequencies on the submicrometer propagation distances in nanocomposites. We discuss the interaction of the quantum-confinement-induced super-resonance with the conventional plasmonic ones, as well as the unusual quantum level statistics, adapting here the paradigms of the quantum billiard theory and showing the possibility to control the resonance position and width using the geometry of the nanostructures.

Spatiotemporal modulation offers a variety of opportunities for light manipulations. In this paper, we propose a way toward arbitrary transformation for pulses sequentially propagating within one waveguide in space via temporal waveguide coupling. The temporal waveguide coupling operation is achieved by spatiotemporally modulating the refractive index of the spatial waveguide with a traveling wave through segmented electrodes. We derive the temporal coupled-mode equations and discuss how systematic parameters affect the temporal coupling coefficients. We further demonstrated a temporal Mach-Zehnder interferometer and universal multiport interferometer, which enables arbitrary unitary transformation for pulses. We showcase a universal approach for transforming pulses among coupled temporal waveguides, which requires only one spatial waveguide under spatiotemporal modulation, and hence provide a flexible, compact, and highly compatible method for optical signal processing in time domain.

In a general optimized measurement scheme for discriminating between nonorthogonal quantum states, the error rate is minimized under the constraint of a fixed rate of inconclusive outcomes (FRIO). This so-called optimal FRIO measurement encompasses the standard and well-known minimum-error and optimal unambiguous (or maximum-confidence) discrimination strategies as particular cases. Here, we experimentally demonstrate the optimal FRIO discrimination between $N=2,3,5$, and 7 equally likely symmetric states of a qubit encoded in photonic path modes. Our implementation consists of applying a probabilistic quantum map which increases the distinguishability between the inputs in a controlled way, followed by a minimum-error measurement on the successfully transformed outputs. The results obtained corroborate this two-step approach and, in our experimental scheme, can be straightforwardly extended to higher dimensions. The optimized measurement demonstrated here will be useful for quantum communication scenarios where the error rate and inconclusive rate must be kept below the levels provided by the respective standard strategies.

A non-Markovian process, in which stochastic evolution of the system depends on its past history, often shows up in soft matter, living cells, and other complex systems. Despite its importance, however, the statistics of first passage time in such systems is not well understood. This is largely due to the fact that most theoretical frameworks are based on Markovian description, and incorporation of the memory effect into the problem remains a challenge. Here, we argue that a key quantity in the problem, i.e., the average behavior of a non-Markovian walker after the first passage, can be linked to its dynamical response, and propose a simple framework to compute important observables in the first passage problem. We perform a mean-field analysis and demonstrate semiquantitative description of the one-dimensional fractional Brownian motion in the presence of an absorbing boundary.

Neuromorphic computing mimics the brain's architecture to create energy-efficient devices. Reconfigurable synapses are crucial for neuromorphic computing, which can be achieved through memory-resistive (memristive) switching. Graphene-based memristors have shown nonvolatile multibit resistive switching with desirable endurance. Through first-principles calculations, we study the structural and electronic properties of graphene in contact with an ultra-thin alumina overlayer and demonstrate how one can use charge doping to exert direct control over its interfacial covalency, reversibly switching between states of conductivity and resistivity in the graphene layer. We further show that this proposed mechanism can be stabilized through the $p$-type doping of graphene, e.g., by naturally occurring defects, the passivation of dangling bonds or defect engineering.

${\mathrm{MgV}}_2{\mathrm{O}}_4$ is a spinel based on magnetic ${\mathrm{V}}^{3+}$ ions, which host both spin $\left(S=1\right)$ and orbital $\left(l_{\mathrm{eff}}=1\right)$ moments. Owing to the underlying pyrochlore coordination of the magnetic sites, the spins in ${\mathrm{MgV}}_2{\mathrm{O}}_4$ only antiferromagnetically order once the frustrating interactions imposed by the $Fd\overline{3}m$ lattice are broken through an orbitally-driven structural distortion at ${\mathrm{T}}_S\simeq 60$ K. Consequently, a Néel transition occurs at ${\mathrm{T}}_N\simeq 40$ K. Low-temperature spatial ordering of the electronic orbitals is fundamental to both the structural and magnetic properties; however, considerable discussion on whether it can be described by complex or real orbital ordering is ambiguous. We apply neutron spectroscopy to resolve the nature of the orbital ground state and characterize hysteretic spin-orbital correlations using x-ray and neutron diffraction. Neutron spectroscopy finds multiple excitation bands and we parametrize these in terms of a multilevel (or excitonic) theory based on the orbitally degenerate ground state. Meaningful for the orbital ground state, we report an “optical-like” mode at high energies that we attribute to a crystal-field-like excitation from the spin-orbital $j_{\mathrm{eff}}=2$ ground-state manifold to an excited $j_{\mathrm{eff}}=1$ energy level. We parametrize the magnetic excitations in terms of a Hamiltonian with spin-orbit coupling and local crystalline electric field distortions resulting from deviations from perfect octahedra surrounding the ${\mathrm{V}}^{3+}$ ions. We suggest that this provides compelling evidence for complex orbital order in ${\mathrm{MgV}}_2{\mathrm{O}}_4$. We then apply the consequences of this model to understand hysteretic effects in the magnetic diffuse scattering where we propose that ${\mathrm{MgV}}_2{\mathrm{O}}_4$ displays a high-temperature orbital memory of the low-temperature spin order.

Genome duplication, transcription, and translation are among many crucial cellular processes that need to be performed with high fidelity. However, those extremely low error rates cannot be explained with simple equilibrium thermodynamic considerations. They instead require considering irreversible, energy-consuming reactions in the overall mechanism. We develop here a model of substrates selection comprising energy-consuming steps which aims at selecting right substrates among wrong ones. With this model, we investigate the impact of energy consumption on the accuracy and the speed of the selection, as well as different selection strategies, by unraveling the molecular steps underlying the discrimination process. The model presented here encompasses the classic kinetic proofreading scheme and a different mechanism whereby the rates of the energy-consuming step are modulated by the nature of the substrate, the catalytic discrimination. We show that, in our framework, the fastest and most accurate selection strategy relies on a combination of both mechanisms, a reliable strategy to overcome the speed-accuracy tradeoff. A structurally and biochemically informed coarse-grained description of real biological processes such as DNA replication and protein translation, traditionally used as examples of kinetic proofreading at work, shows that, as a matter of fact, a combination of both mechanisms explored here is exploited.

Diffusion Monte Carlo calculations on the possibility of having self-bound one-dimensional droplets of SU(6) $\times$ SU(2) ultracold fermionic mixtures are presented. We found that, even though arrangements with attractive interactions with only two spin types are not self-bound, mixtures with at least three kinds of fermions form stable small drops. However, that stabilization decreases for very tight confinements, where a universal behavior is found for Fermi-Fermi and Fermi-Boson clusters including attractive and repulsive interactions.

We extend the theory of shot noise in coherent metals to shot noise in strange metals without quasiparticle excitations. This requires a generalization of the Boltzmann equation with a noise source to distribution functions which depend independently on the excitation momentum and energy. We apply this theory to a model of a strange metal with linear in temperature ($T$) resistivity, describing a Fermi surface with a spatially random Yukawa coupling to a critical boson. We find a suppression of the Fano factor in the strange metal, and describe the dependence of the shot noise on temperature and applied voltage. At low temperatures, we obtain a Fano factor equal to $1/6$, in contrast to the $1/3$ Fano factor in diffusive metals with quasiparticles. Our results are in general agreement with recent observations by Chen et al. (arXiv:2206.00673). We further compare the random Yukawa model to quasi-elastic electron-phonon scattering that also generates $T$-linear resistivity, and argue that shot noise observations offer a useful diagnostic to distinguish between them.

We conduct high-accuracy calculations of isotope shift (IS) factors of the states involving the $D_1$ and $D_2$ lines in Zn II. Together with a global fit to the available optical IS data, we extract nuclear-model independent, precise differential radii for a long chain of Zn isotopes. These radii are compared with the ones inferred from muonic x-ray measurements. Some deviations are found, which we ascribe to the deformed nature of Zn nuclei that introduces nuclear-model dependency into radii extractions from muonic atoms. We arrive at the conclusion that, in cases where the many-body atomic calculations of IS factors are well established, optical determinations of differential radii are more reliable than those from the muonic x-ray measurements, opening the door to obtaining more trustworthy nuclear radii across the nuclear chart.

We investigate ultrafast harmonic generation (HG) in Si:B, driven by intense pump pulses with fields reaching $\sim 100\mathrm{kV}{\mathrm{cm}}^{-1}$ and a carrier frequency of 300 GHz, at 4 K and 300 K, both experimentally and theoretically. We report several findings concerning the nonlinear charge carrier dynamics in intense sub-THz fields: (i) Harmonics of order up to $n=9$ are observed at room temperature, while at low temperature we can resolve harmonics reaching at least $n=11$. The susceptibility per charge carrier at moderate field strength is as high as for charge carriers in graphene, considered to be one of the materials with the strongest sub-THz nonlinear response. (ii) For $T=300$ K, where the charge carriers bound to acceptors are fully thermally ionized into the valence subbands, the susceptibility values decrease with increasing field strength. Simulations incorporating multi-valence-band Monte Carlo and finite-difference-time-domain (FDTD) propagation show that here, the HG process becomes increasingly dominated by energy-dependent scattering rates over the contribution from band nonparabolicity, due to the onset of optical-phonon emission, which ultimately leads to the saturation at high fields. (iii) At $T=4\mathrm{K}$, where the majority of charges are bound to acceptors, we observe a drastic rise of the HG yields for internal pump fields of $\sim 30\mathrm{kV}{\mathrm{cm}}^{-1}$, as one reaches the threshold for tunnel ionization. We disentangle the HG nonlinear response into contributions associated with the initial photoionization and subsequent motion in the bands, and show that intracycle scattering seriously degrades any contribution to HG emission from coherent recollision of the holes with their parent ions.

Bulk acoustic wave (BAW) resonators are attractive as intermediaries in a microwave-to-optical transducer, due to their long coherence times and controllable coupling to optical photons and superconducting qubits. However, for an optomechanical transducer to operate without detrimental added noise, the mechanical modes must be in the quantum ground state. This has proven challenging in recent demonstrations of transduction based on other types of mechanical resonators, where absorption of laser light caused heating of the phonon modes. In this work, we demonstrate ground-state operation of a Brillouin optomechanical system composed of a quartz BAW resonator inside an optical cavity. We show optomechanical coupling to several phonon modes and perform sideband asymmetry thermometry to demonstrate a thermal occupation below 0.5 phonons at base temperature. This constitutes the heaviest ($\sim 494\mu \mathrm{g}$) mechanical object measured in the quantum ground state to date. Further measurements confirm a negligible effect of laser heating on this phonon occupation. Our results pave the way toward low-noise, high-efficiency microwave-to-optical transduction based on BAW resonators.