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Quantum nonlinear operations for harmonic oscillator systems play a key role in the development of analog quantum simulators and computers. Since a variety of strong highly nonlinear operations are unavailable in the existing physical…

Quantum Physics · Physics 2017-09-25 Kimin Park , Petr Marek , Radim Filip

We study the implementation of quantum channels with quantum computers while minimizing the experimental cost, measured in terms of the number of Controlled-NOT (C-NOT) gates required (single-qubit gates are free). We consider three…

Quantum Physics · Physics 2017-05-17 Raban Iten , Roger Colbeck , Matthias Christandl

The no-quantum broadcasting theorem which is a weaker version of the nocloning theorem restricts us from broadcasting completely unknown quantum information to multiple users. However, if the sender is aware of the quantum information…

Quantum Physics · Physics 2023-05-02 Satish Kumar , Anirban Pathak

We present some results from simulation of a network of nodes connected by c-NOT gates with nearest neighbors. Though initially we begin with pure states of varying boundary conditions, the updating with time quickly involves a complicated…

Quantum Physics · Physics 2007-05-23 Fariel Shafee

We prove that it is impossible to built a universal quantum machine that produces reflections about an unknown state. We then point out a connection between this result and the optimality of Grover's search algorithm: if such reflection…

Quantum Physics · Physics 2011-05-23 Karthikeyan S. Kumar , G. S. Paraoanu

We prove a general limitation in quantum information that unifies the impossibility principles such as no-cloning and no-anticloning. Further, we show that for an unknown qubit one cannot design a universal Hadamard gate for creating equal…

Quantum Physics · Physics 2009-11-07 Arun K. Pati

An indistinguishability obfuscator is a probabilistic polynomial-time algorithm that takes a circuit as input and outputs a new circuit that has the same functionality as the input circuit, such that for any two circuits of the same size…

Quantum Physics · Physics 2021-11-11 Anne Broadbent , Raza Ali Kazmi

An explicit algorithm for calculating the optimized Euler angles for both qubit state transfer and gate engineering given two arbitary fixed Hamiltonians is presented. It is shown how the algorithm enables us to efficiently implement single…

Quantum Physics · Physics 2009-12-03 K. Ch. Chatzisavvas , G. Chadzitaskos , C. Daskaloyannis , S. G. Schirmer

We show how it is possible to realize quantum computations on a system in which most of the parameters are practically unknown. We illustrate our results with a novel implementation of a quantum computer by means of bosonic atoms in an…

Quantum Physics · Physics 2007-05-23 J. J. Garcia-Ripoll , J. I. Cirac

We give a natural problem over input quantum oracles $U$ which cannot be solved with exponentially many black-box queries to $U$ and $U^\dagger$, but which can be solved with constant many queries to $U$ and $U^*$, or $U$ and…

Quantum Physics · Physics 2026-05-11 Ewin Tang , John Wright , Mark Zhandry

Quantum circuit optimization - the process of transforming a quantum circuit into an equivalent one with reduced time and space requirements - is crucial for maximizing the utility of current and near-future quantum devices. While most…

Quantum Physics · Physics 2026-01-23 Marcin Szyniszewski , Aleks Kissinger , Noah Linden , Paul Skrzypczyk

We introduce a novel algorithm for the task of coherently controlling a quantum mechanical system to implement any chosen unitary dynamics. It performs faster than existing state of the art methods by one to three orders of magnitude…

Quantum Physics · Physics 2015-06-04 Pierre de Fouquieres

Coherent quantum rollout for sequential decision problems requires a unitary simulator: randomness must live in explicit quantum registers, and basis-state selectors must be mapped to actions reversibly. With branch-dependent valid actions,…

Quantum Physics · Physics 2026-04-30 Nishant Shukla

A new method for compiling quantum algorithms is proposed and tested for a three qubit system. The proposed method is to decompose a a unitary matrix U, into a product of simpler U j via a neural network. These U j can then be decomposed…

Quantum Physics · Physics 2017-10-11 Michael Swaddle , Lyle Noakes , Liam Salter , Harry Smallbone , Jingbo Wang

Many quantum algorithms make use of oracles which evaluate classical functions on a superposition of inputs. In order to facilitate implementation, testing, and resource estimation of such algorithms, we present quantum circuits for…

Quantum Physics · Physics 2018-06-01 Thomas Häner , Martin Roetteler , Krysta M. Svore

The controlled-not gate and the single qubit gates are considered elementary gates in quantum computing. It is natural to ask how many such elementary gates are needed to implement more elaborate gates or circuits. Recall that a…

Quantum Physics · Physics 2007-05-23 Guang Song , Andreas Klappenecker

Quantum random numbers are essential for security against quantum algorithms. Randomness as a beacon is a service being provided for companies and governments to upgrade their security standards from RSA to PQC-QKD or PQC-RSA protocols.…

Quantum Physics · Physics 2025-04-30 Vardaan Mongia , Abhishek Kumar , Shashi Prabhakar , R. P. Singh

One-way quantum computing is a promising candidate for fault-tolerant quantum computing. Here, we propose new protocols to realize a deterministic one-way CNOT gate and one-way $X$-rotations on quantum-computing platforms. By applying a…

Recursive techniques have recently been introduced into quantum programming so that a variety of large quantum circuits and algorithms can be elegantly and economically programmed. In this paper, we present a proof system for formal…

Quantum Physics · Physics 2024-11-08 Mingsheng Ying , Zhicheng Zhang

The encoding of classical to quantum data mapping through trigonometric functions within arithmetic-based quantum computation algorithms leads to the exploitation of multivariate distributions. The studied variational quantum gate learning…

Quantum Physics · Physics 2025-11-12 Ziqing Guo , Jan Balewski , Wenshuo Hu , Alex Khan , Ziwen Pan