English
Related papers

Related papers: Spacetime-Efficient Low-Depth Quantum State Prepar…

200 papers

Quantum state preparation is an important subroutine for quantum computing. We show that any $n$-qubit quantum state can be prepared with a $\Theta(n)$-depth circuit using only single- and two-qubit gates, although with a cost of an…

Quantum Physics · Physics 2023-04-25 Xiao-Ming Zhang , Tongyang Li , Xiao Yuan

The preparation of $n$-qubit quantum states is a cross-cutting subroutine for many quantum algorithms, and the effort to reduce its circuit complexity is a significant challenge. In the literature, the quantum state preparation algorithm by…

Quantum Physics · Physics 2026-02-09 Giacomo Belli , Michele Amoretti

A crucial subroutine in quantum computing is to load the classical data of $N$ complex numbers into the amplitude of a superposed $n=\lceil \log_2N\rceil$-qubit state. It has been proven that any algorithm universally implementing this…

Quantum Physics · Physics 2021-08-13 Xiao-Ming Zhang , Man-Hong Yung , Xiao Yuan

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 Quantum State Preparation problem aims to prepare an $n$-qubit quantum state $|\psi_v\rangle =\sum_{k=0}^{2^n-1}v_k|k\rangle$ from the initial state $|0\rangle^{\otimes n}$, for a given unit vector $v=(v_0,v_1,v_2,\ldots,v_{2^n-1})^T\in…

Quantum Physics · Physics 2023-02-23 Xiaoming Sun , Guojing Tian , Shuai Yang , Pei Yuan , Shengyu Zhang

Minimizing the use of CNOT gates in quantum state preparation is a crucial step in quantum compilation, as they introduce coupling constraints and more noise than single-qubit gates. Reducing the number of CNOT gates can lead to more…

Information Theory · Computer Science 2024-09-05 Hanyu Wang , Bochen Tan , Jason Cong , Giovanni De Micheli

Quantum state preparation is a critical task in quantum computing, particularly in fields such as quantum machine learning, Hamiltonian simulation, and quantum algorithm design. The depth of preparation circuit for the most general state…

Quantum Physics · Physics 2025-08-21 Yu Li , Guojing Tian , Xiaoyu He , Xiaoming Sun

In quantum computation every unitary operation can be decomposed into quantum circuits-a series of single-qubit rotations and a single type entangling two-qubit gates, such as controlled-NOT (CNOT) gates. Two measures are important when…

Quantum Physics · Physics 2011-03-07 Martin Plesch , Časlav Brukner

We introduce a versatile method for preparing a quantum state whose amplitudes are given by some known function. Unlike existing approaches, our method does not require handcrafted reversible arithmetic circuits, or quantum table reads, to…

Quantum Physics · Physics 2025-07-10 Sam McArdle , András Gilyén , Mario Berta

Quantum state preparation is a central primitive in many quantum algorithms, yet it is generally resource intensive, with efficient constructions known only for structured families of states. This work introduces a method for preparing…

Quantum Physics · Physics 2026-03-26 Baptiste Claudon , Alexis Lucas , Jean-Philip Piquemal , César Feniou , Julien Zylberman

Loading classical data into quantum registers is one of the most important primitives of quantum computing. While the complexity of preparing a generic quantum state is exponential in the number of qubits, in many practical tasks the state…

Quantum Physics · Physics 2022-09-02 Fereshte Mozafari , Giovanni De Micheli , Yuxiang Yang

We present a protocol for encoding $N$ real numbers stored in $N$ memory registers into the amplitudes of the quantum superposition that describes the state of $\log_2N$ qubits. This task is one of the main steps in quantum machine learning…

Quantum Physics · Physics 2022-02-07 Sahel Ashhab

Cat states are an important resource for fault-tolerant quantum computing, where they serve as building blocks for a variety of fault-tolerant primitives. Consequently, the ability to prepare high-quality cat states at large fault distances…

Quantum Physics · Physics 2026-01-08 Tom Peham , Erik Weilandt , Robert Wille

Quantum state preparation is a fundamental and significant subroutine in quantum computing. In this paper, we conduct a systematic investigation on the circuit size (the total count of elementary gates in the circuit) for sparse quantum…

Quantum Physics · Physics 2025-10-10 Lvzhou Li , Jingquan Luo

Many quantum algorithms make use of ancilla, additional qubits used to store temporary information during computation, to reduce the total execution time. Quantum computers will be resource-constrained for years to come so reducing ancilla…

Quantum Physics · Physics 2020-02-26 Jonathan M. Baker , Casey Duckering , Frederic T. Chong

The $n$-qubit $k$-weight Dicke states $|D^n_k\rangle$, defined as the uniform superposition of all computational basis states with exactly $k$ qubits in state $|1\rangle$, form a basis of the symmetric subspace and represent an important…

Quantum Physics · Physics 2025-05-22 Pei Yuan , Shengyu Zhang

Quantum state preparation (QSP) is a key component in many quantum algorithms. In particular, the problem of sparse QSP (SQSP) $\unicode{x2013}$ the task of preparing the states with only a small number of non-zero amplitudes…

Quantum Physics · Physics 2025-09-01 Yao-Cheng Lu , Han-Hsuan Lin

Compared to general quantum states, the sparse states arise more frequently in the field of quantum computation. In this work, we consider the preparation for $n$-qubit sparse quantum states with $s$ non-zero amplitudes and propose two…

Quantum Physics · Physics 2024-04-10 Rui Mao , Guojing Tian , Xiaoming Sun

We study the approximate state preparation problem on noisy intermediate-scale quantum (NISQ) computers by applying a genetic algorithm to generate quantum circuits for state preparation. The algorithm can account for the specific…

Quantum Physics · Physics 2023-05-10 Tom Rindell , Berat Yenilen , Niklas Halonen , Arttu Pönni , Ilkka Tittonen , Matti Raasakka

Quantum state preparation (QSP) for a general $n$-qubit state requires $O(2^n)$ CNOT gates and circuit depth, making exact amplitude encoding (EAE) impractical for near-term quantum hardware. We introduce an ancilla-free hybrid…

Quantum Physics · Physics 2025-12-02 Emad Rezaei Fard Boosari , Maryam Afsary
‹ Prev 1 2 3 10 Next ›