BINA

We design monitored quantum walks with the aim of optimizing state transfer and target search. We show how to construct walks with the property that all the eigenvalues of the non-Hermitian survival operator, describing the mixed effect of unitary dynamics and the back-action of measurement, coalesce to zero, corresponding to an exceptional point whose degree is the size of the Hilbert space. Generally, this search is guaranteed to succeed in a bounded time for any initial condition. It also performs better than the classical random walk search or quantum search on typical graphs. For example, a crawler can be designed such that, starting on a node of the graph, the walker is detected on any of the nodes with probability one at predetermined times. It also allows perfect quantum state transfer from one node of the system to any other, with or without monitoring. Interestingly, this crawler is described as a massless Dirac quasi-particle.

Coplanar microwave resonators made of NbN and YBa 2 Cu 3 O 7-δ show similar behavior under the influence of magnetic field. In particular, the two resonators exhibit marked difference between zero-field-cooled (ZFC) and field-cooled (FC) measurements, which is attributed to the presence of screening currents in ZFC but not in FC measurements.

Possible routes for intra-cluster bond formation (ICBF) in protonated serine dimers have been studied. We found no evidence of ICBF following low energy collision induced dissociation (in correspondence with previous works), however, we do observe clear evidence for ICBF following photon absorption in the eV range. Moreover, the comparison of photon induced dissociation measurements of the protonated serine dimer to those of a protonated serine dipeptide provides evidence that ICBF, in this case, involves peptide bond formation (PBF). The experimental results are supported by {\it ab initio} molecular dynamics and exploration of several excited state potential energy surfaces, unravelling a pathway for PBF following photon absorption. The combination of experiments and theory provides insight into the PBF mechanisms in clusters of amino acids, and reveals the importance of electronic excited states reached upon UV/VUV light excitation.

Novel nanomaterials are of interest in biology, medicine, and imaging applications. Multimodal fluorescent-magnetic nanoparticles demand special attention because they have the potential to be employed as diagnostic and medication-delivery tools, which, in turn, might make it easier to diagnose and treat cancer, as well as a wide variety of other disorders. The most recent advancements in the development of magneto-fluorescent nanocomposites and their applications in the biomedical field are the primary focus of this review. We describe the most current developments in synthetic methodologies and methods for the fabrication of magneto-fluorescent nanocomposites. The primary applications of multimodal magneto-fluorescent nanoparticles in biomedicine, including biological imaging, cancer treatment, and drug administration, are covered in this article, and an overview of the future possibilities for these technologies is provided.

Disorder-induced feedback makes random lasers very susceptible to any changes in the scattering medium. The sensitivity of the lasing modes to perturbations in the disordered systems has been utilized to map the regions of perturbation. A tracking parameter that takes into account the cumulative effect of changes in the spatial distribution of the lasing modes of the system has been defined to locate the region in which a scatterer is displaced by a few nanometers. We show numerically that the precision of the method increases with the number of modes. The proposed method opens up the possibility of application of random lasers as a tool for monitoring locations of nanoscale displacement, which can be useful for single-particle detection and monitoring.

During reproduction, male and female flies use wing vibration to generate different acoustic signals. Males produce a courtship song before copulation that is easily recognized by unilateral wing vibration. In copula, females produce a distinct sound pattern (copulation song) with both wings. Sexual rejection of immature virgins and aggressive encounters between males are also accompanied by sound pulses generated by wing flicks. Fly song has frequency ranges audible to the human ear and can be directly listened to after appropriate amplification. When displayed in an oscillogram, audio recordings can be mapped on wing-movement patterns and thus provide a fast and precise method to sample and quantify motor behaviors with high temporal resolution. After recording different fly sounds, their effect on behavior can be tested in playback experiments.

As part of the performance characterization of a combined and enhanced new AFM-NSOM tip-photo-detector, diffraction limitations were studied on two complementary samples: a nano-barrier embedded between two nano-apertures and one nano-aperture embedded between two nano-barriers. These consecutive multiple-obstacle scanning paths are part of this challenging specifications study of a new conical-shaped and drilled tip-photodetector, sharing a subwavelength aperture. A super-resolution algorithm feature was added in order to overcome possible obstacles, while scanning the same object with several small angles. The new multi-mode system includes scanning topography, optical imaging and an obstacle-overcoming algorithm. The present article study emphasizes the complexity of nano-scanning multiple-apertures/barriers. Both complementary analytical (Python) and numerical (Comsol …

Classical first-passage times under restart are used in a wide variety of models, yet the quantum version of the problem still misses key concepts. We study the quantum hitting time with restart using a monitored quantum walk. The restart strategy eliminates the problem of dark states, ie, cases where the particle evades detection, while maintaining the ballistic propagation which is important for a fast search. We find profound effects of quantum oscillations on the restart problem, namely, a type of instability of the mean detection time, and optimal restart times that form staircases, with sudden drops as the rate of sampling is modified. In the absence of restart and in the Zeno limit, the detection of the walker is not possible, and we examine how restart overcomes this well-known problem, showing that the optimal restart time becomes insensitive to the sampling period.

Due to their atomic-scale thickness, handling and processing of two-dimensional (2D) materials often require multistep techniques whose complexity hampers their large-scale integration in modern device applications. Here we demonstrate that the laser-induced forward transfer (LIFT) method can achieve the one-step, nondestructive printing of the prototypical 2D material MoS2. By selecting the optimal LIFT experimental conditions, we were able to transfer arrays of MoS2 pixels from a metal donor substrate to a dielectric receiver substrate. A combination of various characterization techniques has confirmed that the transfer of intact MoS2 monolayers is not only feasible, but it can also happen without incurring significant defect damage during the process. The successful transfer of MoS2 shows the broad potential the LIFT technique has in the emerging field of printed electronics, including printed devices based …

Superhydrophobic surfaces are receiving increasing attention due to their real-world applications. However, these surfaces suffer from a lack of durability and complicated synthetic processes. This research uses a combination of a simple in-situ coating process between oxygen-activated polypropylene films and unreacted silane monomers. The in-situ process uses a modified Stöber method with the addition of the surfactant cetyltrimethylammonium bromide (CTAB) which aggregates silica (SiO 2) particles in a basic aqueous solution. This resulted in a layer of covalently bonded hierarchical coating of individual and aggregated SiO 2 “flakes” and particles. These coatings were found to have at least double the surface roughness than samples prepared without CTAB with superhydrophilic properties due to their high surface roughness and hydrophilic surface chemical groups. A second layer of fluorocarbon silane …

Metal–sulfur batteries, especially lithium/sodium–sulfur (Li/Na-S) batteries, have attracted widespread attention for large-scale energy application due to their superior theoretical energy density, low cost of sulfur compared to conventional lithium-ion battery (LIBs) cathodes and environmental sustainability. Despite these advantages, metal–sulfur batteries face many fundamental challenges which have put them on the back foot. The use of ether-based liquid electrolyte has brought metal–sulfur batteries to a critical stage by causing intermediate polysulfide dissolution which results in poor cycling life and safety concerns. Replacement of the ether-based liquid electrolyte by a solid electrolyte (SEs) has overcome these challenges to a large extent. This review describes the recent development and progress of solid electrolytes for all-solid-state Li/Na-S batteries. This article begins with a basic introduction to metal–sulfur batteries and explains their challenges. We will discuss the drawbacks of the using liquid organic electrolytes and the advantages of replacing liquid electrolytes with solid electrolytes. This article will also explain the fundamental requirements of solid electrolytes in meeting the practical applications of all solid-state metal–sulfur batteries, as well as the electrode–electrolyte interfaces of all solid-state Li/Na-S batteries.

Naive males court both virgin and mated females but learn through experience to discriminate between them, thus minimizing futile investments in nonreceptive female flies. In the laboratory, we can exploit the innate courtship enthusiasm of males and manipulate their behavior by placing them with a nonreceptive female (immature virgin females, decapitated mature virgin females, or mature mated females), termed as the courtship suppression/conditioning assay. Early studies showed that male flies that experience failure to mate upon interaction with nonreceptive previously mated females show decreased motivation to court (courtship suppression). Courtship suppression is an important experimental paradigm for studying genes and neuronal circuits that mediate short-and long-term memory. The anti-aphrodisiac male-specific pheromone 11-cis-vaccenyl-acetate plays a key role in this conditioned response, as …

Bacillus cereus sensu lato (Bcsl) strains are widely explored due to their capacity to antagonize a broad range of plant pathogens. These include B. cereus sp. UW85, whose antagonistic capacity is attributed to the secondary metabolite Zwittermicin A (ZwA). We recently isolated four soil and root-associated Bcsl strains (MO2, S−10, S-25, LSTW-24) that displayed different growth profiles and in-vitro antagonistic effects against three soilborne plant pathogens models: Pythium aphanidermatum (oomycete) Rhizoctonia solani (basidiomycete), and Fusarium oxysporum (ascomycete). To identify genetic mechanisms potentially responsible for the differences in growth and antagonistic phenotypes of these Bcsl strains, we sequenced and compared their genomes, and that of strain UW85 using a hybrid sequencing pipeline. Despite similarities, specific Bcsl strains had unique secondary metabolite and chitinase-encoding genes that could potentially explain observed differences in in-vitro chitinolytic potential and anti-fungal activity. Strains UW85, S-10 and S-25 contained a (~500 Kbp) mega-plasmid that harbored the ZwA biosynthetic gene cluster. The UW85 mega-plasmid contained more ABC transporters than the other two strains, whereas the S-25 mega-plasmid carried a unique cluster containing cellulose and chitin degrading genes. Collectively, comparative genomics revealed several mechanisms that can potentially explain differences in in-vitro antagonism of Bcsl strains toward fungal plant pathogens.

Cold atoms hold much promise for the realization of quantum technologies, but still encounter many challenges. In this work we show how the fundamental Casimir-Polder force, by which atoms are attracted to a surface, may be temporarily suppressed by utilizing a specially designed quantum potential, which is familiar from the hydrodynamic or Bohmian reformulations of quantum mechanics. We show that when harnessing the quantum potential via suitable atomic wave-packet engineering, the absorption by the surface can be dramatically reduced. As a result, the probing time of the atoms as sensors can increase. This is proven both analytically and numerically. Furthermore, an experimental scheme is proposed for achieving the required shape for the atomic wave packet. All these may assist existing applications of cold atoms in metrology and sensing and may also enable prospective ones. Finally, these …

Coplanar microwave resonators made of NbN and YBa 2 Cu 3 O 7-δ show similar behavior under the influence of magnetic field. In particular, the two resonators exhibit marked difference between zero-field-cooled (ZFC) and field-cooled (FC) measurements, which is attributed to the presence of screening currents in ZFC but not in FC measurements.

Courtship in Drosophila melanogaster involves a series of innate, complex behaviors that allow male and female flies to exchange sensory information and assess the quality of a potential mate. Although highly robust and stereotypical, courtship behaviors can be modulated by internal state and experience. This protocol describes methods for designing and carrying out experiments that measure courtship performance in single-pair assays, in which a male is paired with a female, or in competitive assays, in which a male is presented with a female and with a male competitor. It also includes approaches for measuring female sexual receptivity during courtship.

Engines are systems and devices that convert one form of energy into another, typically into a more useful form that can perform work. In the classical setup, physical, chemical, and biological engines largely involve the conversion of heat into work. This energy conversion is at the core of thermodynamic laws and principles and is codified in textbook material. In the quantum regime, however, the principles of energy conversion become ambiguous, since quantum phenomena come into play. As with classical thermodynamics, fundamental principles can be explored through engines and refrigerators, but, in the quantum case, these devices are miniaturized and their operations involve uniquely quantum effects. Our work provides a broad overview of this active field of quantum engines and refrigerators, reviewing the latest theoretical proposals and experimental realizations. We cover myriad aspects of these devices, starting with the basic concepts of quantum analogs to the classical thermodynamic cycle and continuing with different quantum features of energy conversion that span many branches of quantum mechanics. These features include quantum fluctuations that become dominant in the microscale, non-thermal resources that fuel the engines, and the possibility of scaling up the working medium's size, to account for collective phenomena in many-body heat engines. Furthermore, we review studies of quantum engines operating in the strong system-bath coupling regime and those that include non-Markovian phenomena. Recent advances in thermoelectric devices and quantum information perspectives, including quantum measurement …

Cold atoms hold much promise for the realization of quantum technologies, but still encounter many challenges. In this work we show how the fundamental Casimir-Polder force, by which atoms are attracted to a surface, may be temporarily suppressed by utilizing a specially designed quantum potential, which is familiar from the hydrodynamic or Bohmian reformulations of quantum mechanics. We show that when harnessing the quantum potential via suitable atomic wave-packet engineering, the absorption by the surface can be dramatically reduced. As a result, the probing time of the atoms as sensors can increase. This is proven both analytically and numerically. Furthermore, an experimental scheme is proposed for achieving the required shape for the atomic wave packet. All these may assist existing applications of cold atoms in metrology and sensing and may also enable prospective ones. Finally, these …

Coupling electromagnetic radiation with matter, e.g., by resonant light fields in external optical cavities, is highly promising for tailoring the optoelectronic properties of functional materials on the nanoscale. Here, we demonstrate that even internal fields induced by coherent lattice motions can be used to control the transient excitonic optical response in CsPbBr3 halide perovskite crystals. Upon resonant photoexcitation, two-dimensional electronic spectroscopy reveals an excitonic peak structure oscillating persistently with a 100-fs period for up to ~2 ps which does not match the frequency of any phonon modes of the crystals. Only at later times, beyond 2 ps, two low-frequency phonons of the lead-bromide lattice dominate the dynamics. We rationalize these findings by an unusual exciton-phonon coupling inducing off-resonant 100-fs Rabi oscillations between 1s and 2p excitons driven by the low-frequency …

We study the motion of an overdamped particle connected to a thermal heat bath in the presence of an external periodic potential in one dimension. When we coarse-grain, ie, bin the particle positions using bin sizes that are larger than the periodicity of the potential, the packet of spreading particles, all starting from a common origin, converges to a normal distribution centered at the origin with a mean-squared displacement that grows as 2 D* t, with an effective diffusion constant that is smaller than that of a freely diffusing particle. We examine the interplay between this coarse-grained description and the fine structure of the density, which is given by the Boltzmann-Gibbs (BG) factor e− V (x)/k B T, the latter being nonnormalizable. We explain this result and construct a theory of observables using the Fokker-Planck equation. These observables are classified as those that are related to the BG fine structure, like the …