Reviewerly/exHarmony huggingface dataset:
Using a Social Robot as a Hotel Assessment Tool

This field study investigates the influence of social robots as a hotel assessment tool on hotel ratings. Based on media equation theory, it is assumed that social robots increase quality and quantity of hotel ratings by triggering politeness rules. We developed a robot application that allowed hotel guests to submit ratings on site together with the robot Pepper. Data from robot interactions are compared with data from TrustYou (online rating platform). Results show the potential of social robots as an assessment tool with a trend towards better overall rating when evaluating a hotel on a robot compared to a website.
Practical Development of a Robot to Assist Cognitive Reconstruction in Psychiatric Day Care

One of the important roles of social robots is to support mental health through conversations with people. In this study, we focused on the column method to support cognitive restructuring, which is also used as one of the programs in psychiatric day care, and to help patients think flexibly and understand their own characteristics. To develop a robot that assists psychiatric day care patients in organizing their thoughts about their worries and goals through conversation, we designed the robot's conversation content based on the column method and implemented its autonomous conversation function. This paper reports on the preliminary experiments conducted to evaluate and improve the effectiveness of this prototype system in an actual psychiatric day care setting, and on the comments from participants in the experiments and day care staff.
Robot-Assisted Word-to-Picture Matching Game for Language Learning

Teaching methods are developing rapidly, offering different ways of teaching languages. The more recent ones are robot-assisted language learning and gamification of learning. There is a great body of research related to teaching English as a second/foreign language to children with the help of technology. Most of these studies integrating robots into the learning process showed that they positively affect the learning process and increase the learning gains of children. This study introduces a robot-assisted word-to-picture matching game for English learning in two different modes. This work aims to propose a robot-assisted game-based English learning activity and compare its two versions: a standard version and a priority selection version. To this end, a within-subject experiment was conducted in which a total of 17 children aged 7 to 8 years old participated. The experiment compared the children's knowledge after each version of the game. The results showed a significant difference in learning gains between the question priority algorithm and the standard game.
Towards a Wave Approach for Value Sensitive Design in Social Robotics

Even though a broad range of social robots are currently available on the market, social robots are not yet an integral part of companies, healthcare providers, or public institutions. This might be due to the fact that the prevalent developer perspective immanently focuses on technological advancements, whereas a human-centered view remains underrepresented. In this paper, we argue that a human-centered perspective which integrates values and beliefs of relevant technology stakeholders needs to complement existing approaches to social robot design. Therefore, we propose to apply value sensitive design (VSD) to improve the process of social robot development and design. Even though VSD has become popular in recent years and it represents an established approach to foster innovative technologies, it has not yet been widely applied in the context of social robotics. Concretely, in this paper we will outline the added value of using VSD for social robots and we will explain how to utilize this methodology to enrich research and practice in social robotics.
Dancing with the Nonhuman

We propose that feminist reconceptualisations of agency and difference could dramatically expand our possibilities for both relating to robots in social scenarios and designing them as social agents. A performative approach to human-robot interaction favors the artefact's relational, participatory capacities over representational attributes to explore the meaning-making potential of human-machine couplings rather than the predefined meaning of an individual robotic agent. We discuss the feminist concepts of intra-action and diffraction and explore how they could expand our understanding of the workings of the interference patterns that characterize human-robot relationships. Our collaborative Machine Movement Lab project serves as a case study to look at the situated enactment of the subjects and objects that shape our human-robot relationships through the embodied lens of performance-making.
Benchmarking the recursive quantum approximate optimization algorithm

Recent results on the Quantum Approximate Optimization Algorithm (QAOA) have cast pessimism on its potential to exhibit practical quantum speedups. For instance, QAOA’s locality limits its performance on tasks such as coloring bipartite graphs—which is easy for classical methods. Motivated by these limitations, the Recursive QAOA was introduced to overcome the locality and symmetry of QAOA. Despite being more powerful than QAOA, RQAOA is fully classically simulable at level-1 depth (p = 1). We report results on RQAOA in this classically simulable regime, benchmarked on random Quantum Unconstrainted Binary Optimization (QUBO) problems with up to 100 variables. We find that RQAOA generally matches the performance of classical simulated annealing and significantly outperforms ordinary QAOA.
High resolution phase-stepping shearography by using a 24 megapixel digital still imaging device

Digital phase-stepping shearography is a modern precision measurement technique for quantifying microscopic displacement gradients and strains of an object surface by interferometric speckle techniques. The phase map of the displacement derivatives of a stressed object is generated using laser speckles in this technique. As a result, the strains of a deformed object can be directly mapped. Phase-stepping shearography is also very useful in industrial non-destructive testing (NDT). In conventional digital phase stepping shearography, a video camera of limited resolution is used for imaging the laser speckles. The maximum resolution of the video camera is only of the order of 5 Megapixels. This limits the spatial resolution for the generated shearograms and phase maps, and consequently, limits the maximum value of the deformations that can be successfully observed in a given situation. We improved the shearography technique and, in particular, performed advanced shearographic experiments with substantially higher spatial resolution than is now achievable. A 24 megapixel still digital image device (DSLR camera) and a Michelson-type shearing setup with an edgeclamped, center-loaded plate are used in this novel technique. Different phase-stepping algorithms were tested, and all of them produced shearograms satisfactory quality. This effectively increases the useful spatial resolution of phase-stepping shearography by roughly 5 times compared to the conventional method using video-rate cameras, and will also improve spatial resolution in many possible applications.
Biphoton spectral quantum interference for information processing and delay metrology

Broadband time-energy entangled photons feature strong temporal correlations with potential for precision delay metrology, but previous work has leveraged only time-of-flight information ultimately limited by the detection jitter and resolution of the time-tagging electronics. Firstly, our work pushes the entanglement-based nonlocal delay metrology from the conventional time-of-flight measurement to a new direction—two-photon interferometry with subpicosecond sensitivity independent of detection resolution. Next, we show the selective sensitivity of frequency-bin encoded Bell states to the sum and difference of biphoton-delays by using a novel reconfigurable setup capable of switching between the Bell states by successively employing single and dual spectral-line pumps.
Coexistent quantum channel characterization using quantum process tomography with spectrally resolved detection

The coexistence of classical and quantum signals over the same optical fiber is critical for quantum networks operating within the existing communications infrastructure. Here, we characterize the quantum channel that results from distributing approximate single-photon polarization-encoded qubits simultaneously with classical light of varying intensities through a 25 km fiber-optic channel. We use spectrally resolved quantum process tomography with a newly developed Bayesian reconstruction method to estimate the quantum channel from experimental data, both with and without classical noise. Furthermore, we show that the coexistent fiber-based quantum channel has high process fidelity with an ideal depolarizing channel if the noise is dominated by Raman scattering. These results aid future development of quantum repeater designs and quantum error-correcting codes which benefit from realistic channel error models.
Hong-Ou-Mandel interference from distinct molecules on the same chip

A major challenge in photonic quantum technologies is two-photon interference from distinct quantum emitters on the same chip. Here, we show and discuss recent results on Hong–Ou–Mandel interference experiments using couples of single organic molecules within few tens of microns, yielding post-selected visibilities of up to 97%. In particular, we discuss the potential interest for future realizations of measurement-device independent quantum key distribution protocols for information-theoretic secure communication.
Long-distance entanglement distribution through satellite intermediary entanglement swapping

Efficient transcontinental entanglement distribution is necessary to build a global quantum network. Without quantum repeaters, distribution through optical fibers is assailed by loss and scattering, limiting the network’s reach to around 100 kilometers. This distance can be greatly extended however, by transmitting photons through free space, where the transmission falls only as the reciprocal square of the propagation distance. Our experiment aims to prove the viability of one proposed satellite intermediary scheme: a down-link architecture using entanglement swapping. In this scheme, a satellite generates a pair of entangled photons that are spectrally unentangled – and therefore able to interfere with other photons. The satellite transmits the telecom pump and the entangled telecom photons down to a station on Earth’s surface; by doing so, both channels experience the same temporal drift due to Doppler shift and dispersion. The transmitted pump can then be collected, reamplified, and used to pump a second terrestrial entanglement source. Synchronizing and interfering the satellite and terrestrial entangled, telecom photons will then swap entanglement to the unused photons. We are implementing this by pumping non-degenerate entanglement sources, which produce daughter photons at 773 nm and 1588 nm, with a 520 nm pump, generated from third harmonic generation.
A wavelength tunable optical transmitter for quantum key distribution

Wavelength tunability in quantum key distribution (QKD) is desirable as noise can be introduced to the quantum channel if there is significant traffic near the same wavelength as the quantum data. Today’s QKD systems are typically of fixed wavelength due to the single-mode lasers used to encode qubits. We present a new optical transmitter design consisting of a multi-modal Fabry Perot laser optically injection locked by a tunable laser, capable of encoding qubits at GHz speeds with a tunable wavelength of &lt; 65 nm and perform proof-of-principle BB84 QKD over a range of wavelengths with secure bit rates of order Mb/s.
Generating transverse-mode entanglement in optical fiber

We report our recent progress in the generation and verification of a transverse-mode Bell state using spontaneous four-wave mixing in a few-mode polarization-maintaining fiber. Utilizing spatial light modulators, we show control over individual four-wave mixing processes through precise beam shaping of the pump transverse mode and verify entanglement via quantum state tomography. We discuss challenges in temporal and frequency distinguishability and illustrate how they can be resolved. This work represents a first step towards creating a versatile fiber-based transverse mode-entangled photon-pair source matched to fiber infrastructure.
Packet-switching in quantum communication: opportunities and challenges

Packet-switching has been widely used in classical fiber networks for better network scalability and efficiency. Recently, we introduced packet-switching as a new paradigm in quantum networking, where quantum payloads are packetized with classical headers to construct hybrid classical-quantum data frames, and the routing decisions are made in a decentralized fashion at individual routers dynamically. While there are tremendous challenges in building a generic packet-switched quantum network, our study shows that it is possible to develop metropolitan size packet-switched quantum key distribution (QKD) networks with today’s technology. This may greatly facilitate the integration of QKD with classical communication networks and accelerate its adoption.
Dual fiber spectrometer for highly non-degenerate entanglement source

NASA is developing quantum metrology capabilities for potential space-based quantum components in future navigation and communications systems. Innate knowledge of component operation is key for the space qualification of these components. This paper focuses on the measurement and analysis of an important characteristic of an entanglement source, the joint spectrum. We describe a spectrometer based on dispersive optical fibers and present experimental measurements of the joint spectrum of a highly non-degenerate SPDC-based entanglement source that emits entangled photons in the near-infrared and telecommunications bands. How the analysis of such a joint spectrum could be applied to the modeling and simulation of entanglement swapping operations as possible extensions of quantum networks is examined. Lastly, we discuss how the separability of the two-photon state is quantified via Schmidt decomposition and how the degree of separability impacts the spectral purity of heralded single-photon emissions.
Quantum cryptography beyond quantum key distribution: variants of quantum oblivious transfer

Modern cryptography is more than sending secret messages, and quantum cryptography is more than quantum key distribution. One example is oblivious transfer, which is interesting partly because it can be used to implement secure multiparty computation. We discuss a protocol for quantum XOR oblivious transfer, and how non-interactive quantum oblivious transfer protocols can be “reversed”, so that oblivious transfer is still implemented from a sender to a receiver, but so that it is the receiver who sends a quantum state to the sender, who measures it, instead of the other way round. This is useful when one party can only prepare and send quantum states, and the other party can only measure them, which is often the case in practical quantum communication systems. Both the “original” XOR oblivious transfer protocol and its reversed version have been implemented optically. We also discuss how quantum random access codes can be connected with quantum oblivious transfer.
Accelerating NISQ variational methods using geometry

We consider the Quantum Natural Gradient Descent (QNGD) scheme which was recently proposed to train variational quantum algorithms. QNGD is Steepest Gradient Descent (SGD) operating on the complex projective space equipped with the Fubini-Study metric. Here we present an adaptive implementation of QNGD based on Armijo’s rule, which is an efficient backtracking line search that enjoys a proven convergence. The proposed algorithm is tested using noisy simulators on three different models with various initializations. Our results show that Adaptive QNGD dynamically adapts the step size and consistently outperforms the original QNGD, which requires knowledge of optimal step size to perform competitively. In addition, we show that the additional complexity involved in performing the line search in Adaptive QNGD is minimal, ensuring the gains provided by the proposed adaptive strategy dominates any increase in complexity. Additionally, our benchmarking demonstrates that a simple SGD algorithm (implemented in the Euclidean space) equipped with the adaptive scheme above, can yield performances similar to the QNGD scheme with optimal step size. Our results are yet another confirmation of the importance of differential geometry in variational quantum computations. As a matter of fact, we foresee advanced mathematics to play a prominent role in the NISQ era in guiding the design of faster and more efficient algorithms.
Femtosecond-laser written universal quantum photonic processors

Photonic integrated circuits (PICs) are a technology with a growing interest in a wide range of applications in quantum information, from computation to communications and sensing. Amongst the various types of PICs, universal quantum photonic processors (UQPPs) are programmable photonic integrated circuits on which any arbitrary unitary transformation can be implemented on a given input quantum photonic state, sometimes also referred to as quantum photonic FPGAs. Various kinds of UQPPs have been reported, mostly with a reconfigurable Mach-Zehnder interferometer (MZI) as building block, in photonic platforms ranging from silicon nitride to glass-based direct laser writing. Among them, femtosecond laser writing (FLW) is a versatile fabrication technique that allows for cost-effective fabrication of waveguides in glass substrates with low insertion losses (down to 0.1 dB cm<sup>−1</sup> for the propagation and 0.2 dB per facet for the coupling) over a wide wavelength range, a key requirement for quantum applications. Moreover, FLW allows for the fabrication of microstructures in the substrate such as trenches, which can act as thermal isolation structures that significantly reduce the power dissipation of thermal phase shifters and their thermal crosstalk. In this work, firstly we present the fabrication of a 6-mode FLW-UQPP in a rectangular MZI mesh layout operating at 785 nm with average amplitude fidelity as high as 0.9963 when implementing switching unitaries and 0.9979 when implementing Haar random unitaries. Secondly, we demonstrate the versatility of the FLW platform by fabricating another 6-mode UQPP with waveguides optimized for operation at 1550 nm wavelength, with similar performance, on which we repeated the implementation of Haar random unitaries with 0.9969 average amplitude fidelity.
Double exposure ESPI for non-contact surface topography tracking

In this paper, we introduce an electronic speckle pattern interferometry (ESPI) method for rapid assessment of transient deformations on an opaque object. The method records the change in speckle patterns over time, which relate to the change in phase of the reflected light. The system was capable of high-speed recordings enabled by a camera capable of double exposure and external triggering. Experiments were performed on an opaque PDMS phantom to track rapid surface movements from a piezoelectric acoustic driver located at the back of phantom. Acoustic pulses of different period and amplitude were tested. In each double exposure recording cycle, the image pair were digitally subtracted to reveal the change in the speckle pattern, which represented the change in phase of the object beam relative to the reference. We developed custom software to process the data, including an algorithm to unwrap the phase maps. Experiments revealed an ultimate sensitivity to displacements of approximately 1 nm for signals ranging in period from 50 &mu;s to 200 &mu;s. Future work will examine the capabilities of the system with respect to surfaces with different optical absorption and scattering characteristics.
Imaging system for leak detection using collimated white/color LED light

We propose an imaging system and method for leakage detection in the consumer electronics manufacturing industry that uses Schlieren imaging with a collimated beam emitted from a white/color LED as a back illumination light to image, locate and characterize a flow of pressurized gas with a refractive index different than that of ambient air from certain leak areas of a sealed device under test (DUT). In particular, the Schlieren imaging system includes a collimated light, a knifeedge spatial filter and a 4F telescopic imaging system used to create an image of the DUT, which is pressurized and monitored for leaks. When a leak is present and in the monitored plane of the DUT, contrast variation reveals the presence, location, and characteristics of the leak. For example, we can evaluate a waterproof/leakproof mobile device for leakage between layers of modules, such as leaks in the housing of a waterproof electronics case. This detection method can allow identification and characterization of leak points via visual identification, where we use a fiber-coupled LED as a light source to create high quality collimated light for the best Fourier filter effect for a 4F imaging system. Our application shows that LED light has sufficient chromatic quality to act as a light source for a Schlieren imaging system with high sensitivity.
Line-field white light interferometer with tunable-path-difference source controlled by fiber stretcher

White light interferometry (WLI) is the 3D imaging sensor based on interferometry to obtain depth information by acquiring constructive interference. It allows a deep scanning range in high resolution while there are still limitations that lead to a low imaging speed and vibration from the mechanical movement. In this study, we resolved the vibration problem by isolating the depth scanning part in the tunable-path-difference source (TPDS) with a fiber stretcher from the interferometric measurement part. We also applied line-field interferometry to improve scanning speed and to image not only flat surfaces but also curved objects in variable fields of view.
Field-trial quantum key distribution between Sicily and Malta

Quantum key distribution (QKD) is the first commercial application of the second quantum revolution. Although QKD systems have already been developed and implemented all around the world, some open challenges are limiting the overall deployment of this technology (limited key rate, limited link distance, etc.). By improving the current QKD protocols, it is possible to increase the final secret key generation rate. In this work, we compare 1-decoy with 2-decoy methods in BB84 protocol over an underwater optical fiber link connecting Malta to Italy, showing that 2-decoy can achieve more than twice the key rate of 1-decoy method.
Comparison of high speed quantum random number generators based on ASE-ASE and ASE-LASER beating

We report two Quantum Random Number Generator (QRNG) schemes based on Amplified Spontaneous Emission (ASE) to address the problems of previous ASE based QRNGs – (1) costlier and commercially difficult-to-get components, (2) higher electrical noise in the faster detectors. Our ASE-ASE-beating based QRNG, built using commercially available components, clocks in 7.437Gbps random number generation rate. Our second QRNG scheme based on the beating of LASER and ASE of similar power generates random bits at a speed of 7.80Gbps. The minimum entropy values for these schemes are 5.21 and 5.4990 respectively for an 8-bit ADC. The second scheme reports higher entropy because its random numbers has a higher variance than first one. We use the Toeplitz extractor on the raw bits to generate unbiased random numbers and verify them with the help of industry-standard statistical tests.