English
Related papers

Related papers: Three-Qubit State Preparation: Classification and …

200 papers

This work proposes numerical tests which determine whether a two-qubit operator has an atypically simple quantum circuit. Specifically, we describe formulae, written in terms of matrix coefficients, characterizing operators implementable…

Quantum Physics · Physics 2009-11-10 Vivek V. Shende , Stephen S. Bullock , Igor L. Markov

We present a way of identifying all kinds of entanglement for three-qubit pure states in terms of the expectation values of Pauli operators. The necessary and sufficient conditions to classify the fully separable, biseparable, and genuine…

Quantum Physics · Physics 2015-06-12 Ming-Jing Zhao , Ting-Gui Zhang , Xianqing Li-Jost , Shao-Ming Fei

Ubiquitous in quantum computing is the step to encode data into a quantum state. This process is called quantum state preparation, and its complexity for non-structured data is exponential on the number of qubits. Several works address this…

Quantum Physics · Physics 2023-07-28 Israel F. Araujo , Carsten Blank , Ismael C. S. Araújo , Adenilton J. da Silva

We present a low-depth amplitude encoding method for arbitrary quantum state preparation. Building on the foundation of an existing divide-and-conquer algorithm, we propose a method to disentangle the ancillary qubits from the final state.…

Quantum Physics · Physics 2025-10-10 Roselyn Nmaju , Fiona Speirits , Sarah Croke

The preparation of quantum states lies at the foundation in the quantum information processing. The convex mixing of some existing quantum states is one of the effective candidate. In this paper, we mainly study how a target quantum state…

Quantum Physics · Physics 2022-03-16 Li-qiang Zhang , Deng-hui Yu , Chang-shui Yu

We consider the implementation of two-qubit unitary transformations by means of CNOT gates and single-qubit unitary gates. We show, by means of an explicit quantum circuit, that together with local gates three CNOT gates are necessary and…

Quantum Physics · Physics 2009-11-10 G. Vidal , C. M. Dawson

A complete analysis of entangled bipartite qutrit pure states is carried out based on a simple entanglement measure. An analysis of all possible extremally entangled pure bipartite qutrit states is shown to reduce, with the help of SLOCC…

Quantum Physics · Physics 2009-11-11 Feng Pan , Guoying Lu , J. P. Draayer

We experimentally demonstrate an optical controlled-NOT (CNOT) gate with arbitrary single inputs based on a 4-photon 6-qubit cluster state entangled both in polarization and spatial modes. We first generate the 6-qubit state, and then by…

A large-scale quantum circuit can be partitioned into multiple subcircuits through circuit cutting, where each subcircuit is executed multiple times and the expectation value of the original circuit is reconstructed by classical…

Quantum Physics · Physics 2026-03-30 Ryota Tamura , Tomoya Kashimata , Yohei Hamakawa , Kosuke Tatsumura , Hiroshi Imai

Recently, several similar protocols[J. Opt. B 4 (2002) 380; Phys. Lett. A 316 (2003) 159; Phys. Lett. A 355 (2006) 285; Phys. Lett. A 336 (2005) 317] for remotely preparing a class of multi-qubit states (i.e, $\alpha|0 ... 0>+\beta|1...…

Quantum Physics · Physics 2007-08-21 Zhan-jun Zhang

In scenarios where full access to all qubits of a multipartite quantum system is available and global operations can be implemented, the preparation of arbitrary entangled states is theoretically straightforward. However, practical…

Quantum Physics · Physics 2025-08-13 Bibhuti Thapa , Oberon Moran , Duc-Kha Vu , Fatih Ozaydin

The Dicke state $|D_k^n\rangle$ is an equal-weight superposition of all $n$-qubit states with Hamming Weight $k$ (i.e. all strings of length $n$ with exactly $k$ ones over a binary alphabet). Dicke states are an important class of entangled…

Quantum Physics · Physics 2020-08-27 Andreas Bärtschi , Stephan Eidenbenz

Quantum state preparation is a fundamental component of quantum algorithms, particularly in quantum machine learning and data processing, where classical data must be encoded efficiently into quantum states. Existing amplitude encoding…

Quantum Physics · Physics 2026-02-11 Carsten Blank , Israel F. Araujo

Quantum state preparation is an important class of quantum algorithms that is employed as a black-box subroutine in many algorithms, or used by itself to generate arbitrary probability distributions. We present a novel state preparation…

Quantum Physics · Physics 2020-06-02 Yutaro Iiyama

Quantum states that are symmetric under particle exchange play a crucial role in fields such as quantum metrology and quantum error correction. We use a variational circuit composed of global one-axis twisting and global rotations to…

We consider the problem of correctly classifying a given quantum two-level system (qubit) which is known to be in one of two equally probable quantum states. We assume that this task should be performed by a quantum machine which does not…

Quantum Physics · Physics 2019-07-02 Marco Fanizza , Andrea Mari , Vittorio Giovannetti

In this work we propose a novel numerical approach to decompose general quantum programs in terms of single- and two-qubit quantum gates with a $CNOT$ gate count very close to the current theoretical lower bounds. In particular, it turns…

Quantum Physics · Physics 2022-05-18 Péter Rakyta , Zoltán Zimborás

We provide a method for compiling approximate multi-controlled single qubit gates into quantum circuits without ancilla qubits. The total number of elementary gates to decompose an n-qubit multi-controlled gate is proportional to 32n, and…

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

Quantum circuits currently constitute a dominant model for quantum computation. Our work addresses the problem of constructing quantum circuits to implement an arbitrary given quantum computation, in the special case of two qubits. We…

Quantum Physics · Physics 2009-11-07 Stephen S. Bullock , Igor L. Markov