English
Related papers

Related papers: Unitary designs in nearly optimal depth

200 papers

The Quantum Approximate Optimization Algorithm and its generalization to Quantum Alternating Operator Ansatz (QAOA) is a promising approach for applying quantum computers to challenging problems such as combinatorial optimization and…

Quantum Physics · Physics 2023-07-25 Vladimir Kremenetski , Anuj Apte , Tad Hogg , Stuart Hadfield , Norm M. Tubman

We present a quantum algorithm for multiplying two $n$-bit integers with overall circuit depth and $T$-depth both bounded by $O(\log^{2} n)$, while using $O(n^{2})$ gates and ancillary qubits. Our construction generates partial products via…

Quantum Physics · Physics 2026-04-14 Fred Sun , Anton Borissov

Quantum optimization solvers typically rely on one-variable-to-one-qubit mapping. However, the low qubit count on current quantum computers is a major obstacle in competing against classical methods. Here, we develop a qubit-efficient…

Quantum Physics · Physics 2026-03-24 Bhuvanesh Sundar , Maxime Dupont

Error filtration is a hardware scheme that mitigates noise by exploiting auxiliary qubits and entangling gates. Although both signal and ancillas are subject to local noise, constructive interference(and in some cases post-selection) allows…

Quantum Physics · Physics 2025-10-22 Aaqib Ali , Giovanni Scala , Cosmo Lupo

Within the general context of the architecture in quantum computer design, this paper aims is to provide a general strategy to obtain a block-matrix representation of quantum gates applied to qubits placed in arbitrary positions over an…

Quantum Physics · Physics 2017-11-28 Giuseppe Sergioli

Quantum noise in real-world devices poses a significant challenge in achieving practical quantum advantage, since accurately compiled and executed circuits are typically deep and highly susceptible to decoherence. To facilitate the…

Quantum Physics · Physics 2025-06-13 Yuchen Guo , Shuo Yang

We propose a universal quantum circuit design that can estimate any arbitrary one-dimensional periodic functions based on the corresponding Fourier expansion. The quantum circuit contains N-qubits to store the information on the different…

Quantum Physics · Physics 2021-11-17 Junxu Li , Sabre Kais

Finding solid and practical quantum advantages via noisy quantum devices without error correction is a critical but challenging problem. Conversely, comprehending the fundamental limitations of the state-of-the-art is equally crucial. In…

Quantum Physics · Physics 2026-03-25 Yuxuan Yan , Zhenyu Du , Junjie Chen , Xiongfeng Ma

Estimating the unitarity of an unknown quantum channel $\mathcal{E}$ provides information on how much it is unitary, which is a basic and important problem in quantum device certification and benchmarking. Unitarity estimation can be…

Quantum Physics · Physics 2026-02-23 Kean Chen , Qisheng Wang , Peixun Long , Mingsheng Ying

Quantum simulation of the electronic structure problem is one of the most researched applications of quantum computing. The majority of quantum algorithms for this problem encode the wavefunction using $N$ Gaussian orbitals, leading to…

Random circuits giving rise to unitary designs are key tools in quantum information science and many-body physics. In this work, we investigate a class of random quantum circuits with a specific gate structure. Within this framework, we…

Parallel computation enables multiple processors to execute different parts of a task simultaneously, improving processing speed and efficiency. In quantum computing, parallel gate implementation involves executing gates independently in…

Quantum Physics · Physics 2024-11-20 Boris Arseniev

How to implement quantum oracle with limited resources raises concerns these days. We design two ancilla-adjustable and efficient algorithms to synthesize SAT-oracle, the key component in solving SAT problems. The previous work takes 2m-1…

Quantum Physics · Physics 2022-06-10 Shuai Yang , Wei Zi , Bujiao Wu , Cheng Guo , Jialin Zhang , Xiaoming Sun

The variational quantum eigensolver is one of the most promising algorithms for near-term quantum computers. It has the potential to solve quantum chemistry problems involving strongly correlated electrons, which are otherwise difficult to…

Quantum Physics · Physics 2023-07-18 Luogen Xu , James K. Freericks

The famous Johnson-Lindenstrauss lemma states that for any set of n vectors, there is a linear transformation into a space of dimension O(log n) that approximately preserves all their lengths. In fact, a Haar random unitary transformation…

Quantum Physics · Physics 2018-07-25 Pranab Sen

A long-standing open question in the algorithms and complexity literature is whether there exist sorting circuits of size $o(n \log n)$. A recent work by Asharov, Lin, and Shi (SODA'21) showed that if the elements to be sorted have short…

Data Structures and Algorithms · Computer Science 2021-11-09 Wei-Kai Lin , Elaine Shi

Unitary $t$-designs are `good' finite subsets of the unitary group $U(d)$ that approximate the whole unitary group $U(d)$ well. Unitary $t$-designs have been applied in randomized benchmarking, tomography, quantum cryptography and many…

Quantum Physics · Physics 2020-01-08 Eiichi Bannai , Mikio Nakahara , Da Zhao , Yan Zhu

A central problem in quantum computation is to understand which quantum circuits are useful for exponential speed-ups over classical computation. We address this question in the setting of query complexity and show that for almost any…

Quantum Physics · Physics 2013-04-18 Fernando G. S. L. Brandao , Michal Horodecki

Quantum computing is powerful because unitary operators describing the time-evolution of a quantum system have exponential size in terms of the number of qubits present in the system. We develop a new "Singular value transformation"…

Quantum Physics · Physics 2020-02-21 András Gilyén , Yuan Su , Guang Hao Low , Nathan Wiebe

The unitary coupled cluster (UCC) algorithm is one of the most promising implementations of the variational quantum eigensolver for quantum computers. However, for large systems, the number of UCC factors leads to deep quantum circuits,…

Quantum Physics · Physics 2026-02-17 Jeremy Canfield , Dominika Zgid , J K Freericks