Quantum Preprints

Perfect inline squeezers are both spectrally pure and have identical input and output temporal modes, allowing one to squeeze an arbitrary input quantum state in the sole input mode on which the device acts, while the quantum states of any other modes are unaffected. We study theoretically how to obtain... Read more
Published on: 1970-01-01
To implement quantum information technologies, carefully designed control for preparing a desired state plays a key role. However, in realistic situation, the actual performance of those methodologies is severely limited by decoherence. Therefore, it is important to evaluate how close we can steer the controlled state to a desired target... Read more
Published on: 1970-01-01
Quantum systems in thermal equilibrium are described using Gibbs states. The correlations in such states determine how difficult it is to describe or simulate them. In this article, we show that systems with short-range interactions that are above a critical temperature satisfy a mixing condition, that is that for any... Read more
Published on: 1970-01-01
Entangled light sources for illuminating objects offers advantages over conventional illumination methods by enhancing the detection sensitivity of a reflecting object. The crux of the quantum advantage lies in way we can practically leverage quantum correlations to isolate the background noise and detect the low reflectivity object. In this work... Read more
Published on: 1970-01-01
A key component of variational quantum algorithms (VQAs) is the choice of classical optimizer employed to update the parameterization of an ansatz. It is well recognized that quantum algorithms will, for the foreseeable future, necessarily be run on noisy devices with limited fidelities. Thus, the evaluation of an objective function... Read more
Published on: 1970-01-01
The full characterization of the possible transformations of quantum operations is indispensable to developing algorithms in higher-order quantum computation, which is the quantum version of functional programming. Although universal transformations of unitary operations have been well investigated, their extensions to non-unitary operations are still missing, except for a few examples.... Read more
Published on: 1970-01-01
The study of state revivals has a long history in dynamical systems. We introduce a resource theory to understand the use of state revivals in quantum physics, especially in quantum many-body scarred systems. In this theory, a state is said to contain no amount of resource if it experiences perfect... Read more
Published on: 1970-01-01
We show that universal parity quantum computing employing a recently introduced constant depth decoding procedure is equivalent to measurement-based quantum computation (MBQC) on a bipartite graph using only YZ-plane measurements. We further show that any unitary MBQC using only YZ-plane measurements must occur on a bipartite graph.... Read more
Published on: 1970-01-01
Despite fundamental interests in learning quantum circuits, the existence of a computationally efficient algorithm for learning shallow quantum circuits remains an open question. Because shallow quantum circuits can generate distributions that are classically hard to sample from, existing learning algorithms do not apply. In this work, we present a polynomial-time... Read more
Published on: 1970-01-01
Finding minimal time and establishing the structure of the corresponding optimal controls which can transfer a given initial state of a quantum system into a given target state is a key problem of quantum control. In this work, this problem is solved for a basic component of various quantum technology... Read more
Published on: 1970-01-01
Optimizing the controls of quantum systems plays a crucial role in advancing quantum technologies. The time-varying noises in quantum systems and the widespread use of inhomogeneous quantum ensembles raise the need for high-quality quantum controls under uncertainties. In this paper, we consider a stochastic discrete optimization formulation of a binary... Read more
Published on: 1970-01-01
The Schrodinger equation with a Yukawa type of potential is solved analytically. When different boundary conditions are taken into account, a series of solutions are indicated as Bessel function, the first kind of Hankel function and the second kind of Hankel function, respectively. Subsequently, the scattering processes of $K bar{K}^*$... Read more
Published on: 1970-01-01
Quantum repeaters are pivotal in the physical layer of the quantum Internet. For its future development, it is desirable to have quantum repeaters capable of facilitating robust and high-speed communication. In terms of efficiency, quantum repeater schemes based on single-photon interference are seen as promising. However, this method, involving first-order... Read more
Published on: 1970-01-01
We analyze the entropy production of Quantum Reset Models (QRMs) corresponding to quantum dynamical semigroups driven by Lindbladians motivated by a probabilistic description of dissipation in an external environment. We investigate the strict positivity of entropy production for Lindbladians given as sums of QRMs, when the Hamiltonian of the total... Read more
Published on: 1970-01-01
Other than the commonly used Wilson's regularization of quantum field theories (QFTs), there is a growing interest in regularizations that explore lattice models with a strictly finite local Hilbert space, in anticipation of the upcoming era of quantum simulations of QFTs. A notable example is Euclidean qubit regularization, which provides... Read more
Published on: 1970-01-01
This thesis actively focuses on designing, analyzing, and experimentally implementing various QST and QPT protocols using an NMR ensemble quantum processor and superconducting qubit-based IBM cloud quantum processor. Part of the thesis also includes a study of duality quantum simulation algorithms and Sz-Nagy's dilation algorithm on NMR where several 2-qubit... Read more
Published on: 1970-01-01
Entropy is a measure of the randomness of a system. Estimating the entropy of a quantum state is a basic problem in quantum information. In this paper, we introduce a time-efficient quantum approach to estimating the von Neumann entropy $S(rho)$ and R'enyi entropy $S_alpha(rho)$ of an $N$-dimensional quantum state $rho$,... Read more
Published on: 1970-01-01
We are dealing with some spectral properties of a phase space localization operator PR corresponding to the indicator function of a disk of radius R < 1. The localization procedure is achieved with respect to a set of negative binomial states (NBS) labeled by points of the complex unit disk... Read more
Published on: 1970-01-01
The proton-neutron interaction is investigated by solving the Schrodinger equation, where a Yukawa type of potential with one pion exchanging between the proton and the neutron is assumed. Since the deutron is the unique bound state of the proton-neutron system, the coupling constant is fixed according to the binding energy... Read more
Published on: 1970-01-01
A general framework in the setting of $C^*$-algebras for the tomographical description of states, that includes, among other tomographical schemes, the classical Radon transform, quantum state tomography and group quantum tomography, is presented. Given a $C^*$-algebra, the main ingredients for a tomographical description of its states are identified: A generalized... Read more
Published on: 1970-01-01