Efficient and robust chiral discrimination by invariant-based inverse engineering.

We propose an accurate and convenient method to achieve 100% discrimination of chiral molecules with Lewis-Riesenfeld invariance. By reversely designing the pulse scheme of handed resolution, we obtain the parameters of the three-level Hamiltonians to achieve this goal. For the same initial state, we can completely transfer its population to one energy level for left-handed molecules, while transferring it to another energy level for right-handed molecules. Moreover, this method can be further optimized when errors exist, and it shows that the optimal method is more robust against these errors than the counterdiabatic and original invariant-based shortcut schemes. This provides an effective, accurate, and robust method to distinguish the handedness of molecules.

Robust coherent control in three-level quantum systems using composite pulses.

Here, we focus on using composite pulses to realize high-robustness and high-fidelity coherent control in three-level quantum systems. We design the dynamic parameters (Rabi frequency and detuning) for three-level Hamiltonians for high-fidelity quantum state control using five well-known coherent control techniques including a composite adiabatic passage (CAP). Furthermore, we compare their performance against the Rabi frequency and systematic errors, and accordingly show that the CAP is the most robust against them. It features a broad range of high efficiencies above 99.9%. Thus, it provides an accurate approach for manipulating the evolution of quantum states in three-level quantum systems.

Color-detuning-dynamics-based quantum sensing with dressed states driving.

Exploring quantum technology to precisely measure physical quantities is a meaningful task for practical scientific researches. Here, we propose a novel quantum sensing model based on color detuning dynamics with dressed states driving (DSD) in stimulated Raman adiabatic passage. The model is valid for sensing different physical quantities, such as magnetic field, mass, rotation and so on. For different sensors, the used systems can range from macroscopic scale, e.g. optomechanical systems, to microscopic nanoscale, e.g. solid spin systems. The dynamics of color detuning of DSD passage indicates the sensitivity of sensors can be enhanced by tuning system with more adiabatic or accelerated processes in different color detuning regimes. To show application examples, we apply our approach to build optomechanical mass sensor and solid spin magnetometer with practical parameters.

Robust stimulated Raman shortcut-to-adiabatic passage with invariant-based optimal control.

The stimulated Raman adiabatic passage shows an efficient technique that accurately transfers population between two discrete quantum states with the same parity in three-level quantum systems based on adiabatic evolution. This technique has widely theoretical and experimental applications in many fields of physics, chemistry, and beyond. Here, we present a general approach to robust stimulated Raman shortcut-to-adiabatic passage with invariant-based optimal control. By controlling the dynamical process, we inversely design a family of Hamiltonians with non-divergent Rabi frequencies that can realize fast and accurate population transfer from the first to the third level, while the systematic errors are largely suppressed in general. Furthermore, a detailed trade-off relation between the population of the intermediate state and the amplitudes of Rabi frequencies in the transfer process is illustrated. These results provide an optimal route toward manipulating the evolution of three-level quantum systems in future quantum information processing.

Estimating quantum steering and Bell nonlocality through quantum entanglement in two-photon systems.

Quantum entanglement, quantum steering and Bell nonlocality, as significant quantum resources in the field of quantum information science, can achieve variously valuable quantum information tasks. Among of them, quantum entanglement and Bell nonlocality are the weakest and strongest nonlocal correlations, respectively. One can capture the quantum steering and Bell nonlocality via violating steering inequality and Bell inequality, respectively. In general, the detections of quantum steering and Bell nonlocality are strictly harder than entanglement detection. Here, based on steering inequality test and quantum state tomography, we attain various nonlocal correlations and experimentally demonstrate that the estimations of quantum steering and Bell nonlocality can be realized according to the quantum entanglement of the prepared two-photon test states. The estimated efficiency of quantum steering is stronger than the one of Bell nonlocality in this scenario, i.e., more steerable two-photon test states can be verified through quantum entanglement. In addition, quantum steering and Bell nonlocality are bounded by the corresponding upper and lower bounds, and these bounds cannot be punctured by all prepared two-photon states in experiment. These results are conducive to understand the relations among these nonlocal correlations.

Fast and robust quantum control for multimode interactions using shortcuts to adiabaticity.

Adiabatic quantum control is a very important approach for quantum physics and quantum information processing (QIP). It holds the advantage with robustness to experimental imperfections but accumulates more decoherence due to the long evolution time. Here, we propose a universal protocol for fast and robust quantum control in multimode interactions of a quantum system by using shortcuts to adiabaticity. The results show this protocol can speed up the evolution of a multimode quantum system effectively, and it can also keep the robustness very good while adiabatic quantum control processes cannot. We apply this protocol for the quantum state transfer in QIP in the photon-phonon interactions in an optomechanical system, showing a perfect result. These good features make this protocol have the capability of improving effectively the feasibility of the practical applications of multimode interactions in QIP in experiment.

Plug-and-Play Approach to Nonadiabatic Geometric Quantum Gates.

Nonadiabatic holonomic quantum computation (NHQC) has been developed to shorten the construction times of geometric quantum gates. However, previous NHQC gates require the driving Hamiltonian to satisfy a set of rather restrictive conditions, reducing the robustness of the resulting geometric gates against control errors. Here we show that nonadiabatic geometric gates can be constructed in an extensible way, called NHQC+, for maintaining both flexibility and robustness against certain types of noises. Consequently, this approach makes it possible to incorporate most of the existing optimal control methods, such as dynamical decoupling, composite pulses, and a shortcut to adiabaticity, into the construction of single-looped geometric gates. Furthermore, this extensible approach of geometric quantum computation can be applied to various physical platforms such as superconducting qubits and nitrogen-vacancy centers. Specifically, we performed numerical simulation to show how the noise robustness in recent experimental implementations [Phys. Rev. Lett. 119, 140503 (2017)PRLTAO0031-900710.1103/PhysRevLett.119.140503; Nat. Photonics 11, 309 (2017)NPAHBY1749-488510.1038/nphoton.2017.40] can be significantly improved by our NHQC+.approach. These results cover a large class of new techniques combing the noise robustness of both geometric phase and optimal control theory.

The Development of Gesture Skills in Chinese Autistic Children: The Predictive Roles of Age and Language Ability.

PURPOSE: Gesture delay in autistic infants and toddlers has been widely reported. The developmental trajectory of gesture production during early childhood is understudied. Thus, little is known about the possible changes of gesture production over time. The present study aimed to document the development of gesture production in autistic children and examine whether child-based factors (chronological age and initial language skills) predicted gesture development. METHOD: A total of 33 Chinese-speaking autistic children (Mage = 56.39 months, SD = 8.54 months) played with their parents at four time points over a 9-month period. Their speech was transcribed, and their gestures were coded from parent-child interaction. Multilevel modeling analysis was used to investigate the development of gesture and its associated factors. RESULTS: The total number of gestures produced by autistic children decreased over time. Among different factors, children's initial age significantly and negatively predicted children's gesture production, while initial language positively predicted children's gesture production. CONCLUSIONS: Gesture delay persists in preschool age. The decline in gesture production was associated with children's age and initial language ability. These findings shed light on the difficulties surrounding gesture use in autistic children.

Evaluating extractable work of quantum batteries via entropic uncertainty relations.

In this study, we investigate the effectiveness of entropic uncertainty relations (EURs) in discerning the energy variation in quantum batteries (QBs) modelled by battery-charger field in the presence of bosonic and fermionic reservoirs. Our results suggest that the extractable works (exergy and ergotropy) have versatile characteristics in different scenarios, resulting in a complex relationship between tightness and extractable work. It is worth noting that the tightness of the lower bound of entropic uncertainty can be a good indicator for energy conversion efficiency in charging QBs. Furthermore, we disclose how the EUR including uncertainty and lower bound contributes to energy conversion efficiency in the QB system. It is believed that these findings will be beneficial for better understanding the role of quantum uncertainty in evaluating quantum battery performance.

Whose Gestures are More Predictive of Expressive Language Abilities among Chinese-Speaking Children with Autism? A Comparison of Caregivers' and Children's Gestures.

In spite of the close relationship between gestures and expressive language, little research has examined the roles of the parents' and children's gestures in the development of expressive language abilities in autistic children. Previous findings are also inconclusive. In the present study, we coded the gestures produced by the parents and their autistic children in parent-child interactions and compared the influence of their gestures on the children's expressive language abilities (N = 35; M = 4;10). Autistic children's deictic gestures positively predicted their Mean Length Utterance (MLU), word types, and word tokens whereas parents' deictic gesture inputs negatively predicted MLU and word types. The findings shed light on the importance of the gestures made by autistic children, which may trigger parents' gesture-to-word translation.

Examining Phenotypical Heterogeneity and its Underlying Factors in Gesture Skills of Chinese Autistic Children: Clustering Analysis.

PURPOSE: The heterogeneity of autism is well documented, but few studies have studied the heterogeneity of gesture production ability in autistic children. The present study aimed to identify subgroups of autistic children who displayed heterogeneous gesture production abilities and explore the underlying factors, including autism characteristics, intellectual ability, and language ability, that were associated with the heterogeneity. METHODS: A total of 65 Chinese autistic children (mean age = 5;3) participated. Their autism characteristics and intellectual ability were assessed by standardized measurements. Language output and gesture production were captured from a parent-child interaction task. RESULTS: We conducted a hierarchical cluster analysis and identified four distinct clusters. Cluster 1 and Cluster 2 both had low gesture production whereas Cluster 3 and Cluster 4 had high gesture production. Both Clusters 1 and 2 had relatively strong autism characteristics, in comparison to Clusters 3 and 4. CONCLUSIONS: Our findings revealed that children with stronger autism characteristics may gesture less often than those with weaker characteristics. However, the relationship between language ability and intellectual ability and gesture production was not clear. These findings shed light on the directions of intervention on gesture production for autistic children, especially those with stronger autism characteristics.

Examining Phenotypical Heterogeneity in Language Abilities in Chinese-Speaking Children with Autism: A Naturalistic Sampling Approach.

Phenotypical heterogeneity in language abilities is a hallmark of autism but remains poorly understood. The present study collected naturalistic language samples from parent-child interactions. We quantified verbal abilities (mean length of utterance, tokens, types) of 50 Chinese-speaking children (M = 5; 6) and stratified subgroups based on their autism traits, IQ, and language abilities. Using hierarchical cluster analysis, four groups were identified. Group 1, the least affected group, had mild autism, the highest IQ, and the strongest verbal abilities. Group 2, the severely affected group, had the lowest IQ, most severe autism symptoms, and weakest verbal abilities. Group 3 and Group 4 displayed average levels of verbal abilities and IQ. These findings may characterize the heterogeneous profiles of verbal abilities in Chinese-speaking children.

The influence of child-based factors and parental inputs on expressive language abilities in children with autism spectrum disorder.

LAY ABSTRACT: Language impairment is one of the early signs of Autism Spectrum Disorder (ASD) that alerts parents to take their children for early diagnosis and intervention. Little is known about how children's autism traits, IQ, initial language abilities and parental inputs influence their language abilities. In addition, only a few studies have compared the relative influence of these factors. The present study addressed these issues by examining the structural language in parent-child spontaneous interactions. Forty-two Cantonese (Chinese)-speaking autistic children aged four to eight were recruited. Their expressive language skills grew rapidly more than 9 months, but their development trajectories varied. Initial expressive language ability is the only significant predictor of child language outcomes and language growth trajectories. In contrast, nonverbal cognition, autism traits, and parents' input do not affect language outcomes in children with ASD. Therefore, early language intervention is crucial for autistic children at all severity and IQ levels.

Environment-mediated entropic uncertainty in charging quantum batteries.

We studied the dynamics of entropic uncertainty in Markovian and non-Markovian systems during the charging of open quantum batteries (QBs) mediated by a common dissipation environment. In the non-Markovian regime, the battery is almost fully charged efficiently, and the strong non-Markovian property is beneficial for improving the charging power. In addition, the results show that the energy storage is closely related to the couplings of the charger-reservoir and battery-reservoir; that is, the stronger coupling of a charger reservoir improves energy storage. In particular, entanglement is required to obtain the most stored energy and is accompanied by the least tight entropic bound. Interestingly, it was found that the tightness of the entropic bound can be considered as a good indicator of the energy transfer in different charging processes, and the complete energy transfer always corresponds to the tightest entropic bound. Our results provide insight into the optimal charging efficiency of QBs during practical charging.

Conversation Skills in Chinese-Speaking Preschoolers with Autism: The Contributing Role of Parents' Verbal Responsiveness.

Children with autism spectrum disorder (ASD) have conversation deficits, yet the growth of conversation abilities is understudied, especially in Chinese-speaking populations. Little is known about whether their parents' verbal responsiveness and redirectives are related to their conversation skills. Children with ASD (N = 37; M = 5;5) and their parents contributed their language samples. These children interacted with their parents at four time points over nine months. The number of conversational turns and the proportion of child-initiated conversation (but not the proportion of children's appropriate responses) grew over nine months. After controlling for time, autism severity, and language skills, parents' verbal responsiveness positively predicted children's appropriate responses. Parents' redirectives negatively predicted the proportion of children's appropriate responses and the number of conversational turns.