This PDF file contains the front matter associated with SPIE Proceedings Volume 12093, including the Title Page, Copyright information, Table of Contents and Conference Committee list.

We study an on-chip quantum computational system with a particular scale in the presence of noise. These conditions can be summarized as “noisy intermediate-scale quantum (NISQ)”. It is a challenge to build reasonable architectures, control flows, and quantum algorithms for the noisy medium-scale quantum conditions, which are highly concern by industry. This paper proposes a quantum computing chip framework that contains both classical and quantum parts. The quantum program developers only focus on the programming design and no need to consider the details of the underlying hardware. This design maintains the transparency for a quantum computer as a classical computer.

We present a computer architecture utilizing codoped Ytterbium-Erbium ions The qubits are generated and entangled in the Ytterbium. The qubits are transferred by energy exchange unto a metastable state of the Erbium. Quantum computation is implemented on the qubits by manipulating their phases with polarized light. A CNOT logic operation is executed to illustrated the main features of the architecture. The quantum computer is robust environment induced decoherence.

In recent years, advances in quantum sensors and sensing protocols have continued to generate interest and development into practical quantum sensing in a number of application domains. A potentially impactful application, namely the detection of time-varying signals in noise or clutter, is a crucial component for advanced radar detection systems and surveillance networks. This particular application was recently introduced in a quantum context, along with optimal control protocols to minimize the detection error rates. Here, we experimentally execute this quantum signal detection protocol and show that it remains effective when applied to real-world communications signals that do not meet the assumptions of the original formulation of the protocol, due to their non-Gaussian nature. We also consider another class of signals motivated by pulsed radar, which presents challenges for the quantum signal detection protocol due to their intermittent nature. Despite this, we demonstrate that additional classical processing of the quantum observations may be used to determine the presence of the signal. These results further extend the potential of quantum sensing techniques to operationally relevant, quantum-enhanced receive chains in passive or bistatic sensing scenarios.

Below 600 km, drag is the largest source of uncertainty for satellite and debris orbit prediction. With an increasing number of satellites in low-Earth orbit, accurate observations of the atmospheric mass density are required to improve models of the thermosphere with applications in satellite lifetime predictions, collision risk assessment and avoidance. We are developing a compact cold atom accelerometer for atmospheric density missions, to be launched in mid to late 2020s. These quantum sensors are based on atom interferometry. A cold atom sample is generated using the combination of an atom-chip and resonant laser beams. The cold atom cloud is then diffracted using a set of three laser pulses, generating a matter-wave interferometer. The phase-shift at the output of the interferometer is proportional to the acceleration of the free falling atoms with respect to the satellite, which is converted to density observations. Teledyne e2v is producing a space suitable accelerometer physics package that can be embedded in small satellites such as a 16U cubesat or a SkimSat. It includes an atom-chip for producing magnetic fields local to the atoms in vacuum developed by RAL Space. It will address some of the engineering challenges associated with the launch and the required low SWAP and will be integrated into a breadboard system capable of acceleration measurement in order to test interferometry schemes suitable for measurements in micro-gravity. Atmospheric drag measurement can be the world’s first cold atom Earth observation mission and be a pathfinder for a future large-scale cold atom gravity mission.

Quantum sensing is an important application of Quantum Information techniques. In this work, we present analytical results for the Quantum Fisher Information of a single Qutrit in the Λ, V, and Ξ configurations of a qutrit with the equidistant energy levels

Quantum random number generation (QRNG) is an important cryptographic primitive. Various security models exist from the fully trusted to the fully device independent scenario. Here we look at the middle-ground of semi source independence (where the only thing known about the source is the dimension) and where measurements are not ideal (e.g., there may be loss and detector inefficiencies). We show how to compute optimistic bit generation rates even in this strong security model and our methods may be broadly applicable to other quantum cryptographic protocols in this setting.

We present a quantum key generation and distribution scheme that utilizes a frequency-comb signal source for key encryption, data encoding and transmission between network users. In this scheme, a frequency is selected randomly from the set of comb frequencies and assigned to a user. Furthermore, another random method is used to encode the randomly selected frequency with user data for key generation. As a result, the key generation is robust against attacks. We shall present practical method for the frequency comb generation and determine the efficiency of the scheme against malicious multiple attacks.

Multi-photon quantum key distribution (QKD) protocols can use non-ideal photon emitters and yet stay secure. As a result, they are advantageous over other single photon prepare and measure QKD schemes. However, their effectiveness has not yet been evaluated in different network topologies. In this paper, we compare the achievable key rates and transmission distances of the three-stage multi-photon QKD protocol to the commonly implemented decoy state and E91 protocols in different network topologies. We also describe the security implications of each protocol especially in relation to a photon number splitting attack against multi-photon sources. Our simulations offer insights into the strengths and weaknesses of each protocol and various trade-offs when using these QKD protocols in different network topologies.

This paper discusses ER = EPR. Given a background space and a quantum tensor network, we describe how to construct a new topological space, that welds the network and the background space together. This construction embodies the principle that quantum entanglement and topological connectivity are intimately related.

Radar and sonar information processing is a promising application area of quantum computing in the near future. Many use cases in this area can are computational heavy and might benefit greatly from a quantum approach. In this paper, an overview of use cases in this application area is given and scored on quantum readiness, added value and expected horizon. From this overview acoustic localisation, generative models, compressive sensing, normalisation and classification are selected as the most promising application areas.

A theoretical architecture for an ultra-wideband, high signal-to-noise ratio RF detector is discussed. The detector combines Rydberg atoms and optical interferometry based on quantum entanglement. Use of entanglement will offer detection sensitivity far exceeding RF detection schemes based on Rydberg atoms created by others. The value of the associated Rydberg state will be evaluated using a master equation. This will include modeling loss, system imperfections, and decay processes using open systems theory. Closed form expressions for the minimum E-field measurable through this process are derived. Measurement limitations on both the Rydberg antenna and quantum interferometer are discussed. Numerical results are discussed.

In the noisy intermediate-scale quantum technological setting, the computational steps in a quantum computer are realized via unitary gates. Gate-model quantum computer architectures can be realized in near-term experimental implementations. Here, we study the model of adaptive problem solving dynamics in gate-model quantum computers.

Kolmogorov complexity of a (classical) string or, more generally, of a (classical) finite object, is defined as the shortest effective binary description of that string or object. Berthiaume, van Dam and Laplante extended the notion of (classical) Kolmogorov complexity to the quantum domain. We introduce the notion of complexity of a quantum density operator and that of a unitary transformation and establish its relation with the qubit complexity of a quantum state.

With the advent of quantum annealers, many quantum computing algorithms are being developed. Solving linear systems is one of the important problems in science and engineering. Recently, a quadratic unconstrained binary optimization (QUBO) model that can implement a linear system in a quantum annealing device has been developed. The developed QUBO model has the advantage in that it can be used for the gate model by using the quantum approximate optimization algorithm. To verify the optimal QUBO model for a linear system, we derive several QUBO models with constrained coefficients for the linear system including the constrained method. We compare and discuss the results for each QUBO model on the D-Wave system.

Superconducting Digital Computing based on Single-Flux-Quantum data encoding is a cryogenic, beyond-CMOS technology with near-term development potential relative to Quantum Computing. Superconducting digital offers 10x improved clock rate and 100x improved power efficiency relative to advanced-node CMOS at scale. The superlative properties of superconducting logic and interconnect give power densities of less than 1W per square cm, enabling 3D packaging with unprecedented computational density. Circuit demonstrations to date have shown progress but remain modest by CMOS standards, scaling the technology will require development of a fabrication stack using novel materials, which would also be applicable to superconducting Quantum implementations