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Related papers: Depth optimization of CZ, CNOT, and Clifford circu…

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Decoherence -- in the current physical implementations of quantum computers -- makes depth reduction a vital task in quantum-circuit design. Moore and Nilsson (SIAM Journal of Computing, 2001) demonstrated that additional qubits -- known as…

Quantum Physics · Physics 2022-09-26 Jiaqing Jiang , Xiaoming Sun , Shang-Hua Teng , Bujiao Wu , Kewen Wu , Jialin Zhang

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

We show that quantum circuits cannot be made fault-tolerant against a depolarizing noise level of approximately 45%, thereby improving on a previous bound of 50% (due to Razborov). Our precise quantum circuit model enables perfect gates…

Quantum Physics · Physics 2007-05-23 Harry Buhrman , Richard Cleve , Monique Laurent , Noah Linden , Alexander Schrijver , Falk Unger

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 provide an $\Omega(log(n))$ lower bound for the depth of any quantum circuit generating the unique groundstate of Kitaev's spherical code. No circuit-depth lower bound was known before on this code in the general case where the gates can…

Quantum Physics · Physics 2018-10-10 Dorit Aharonov , Yonathan Touati

The paper discusses the gate complexity and the depth of reversible circuits consisting of NOT, CNOT and 2-CNOT gates in the case, when the number of additional inputs is limited. We study Shannon's gate complexity function $L(n, q)$ and…

Computational Complexity · Computer Science 2017-03-28 Dmitry V. Zakablukov

We present a scalable set of universal gates and multiply controlled gates in a qudit basis through a bijective mapping from N qubits to qudits with D = 2^N levels via rotations in U(2). For each of the universal gates (H, CNOT, and T), as…

Quantum Physics · Physics 2022-06-16 Pamela Rambow , Mingzhen Tian

In quantum computing the decoherence time of the qubits determines the computation time available and this time is very limited when using current hardware. In this paper we minimize the execution time (the depth) for a class of circuits…

Optimizing quantum circuits by reducing circuit depth is essential for improving the efficiency and scalability of quantum algorithms, particularly as quantum hardware continues to evolve. This can be achieved by restructuring quantum…

Quantum Physics · Physics 2026-05-07 Folkert de Ronde , Stephan Wong , Sebastian Feld

Efficiently implementing Clifford circuits is crucial for quantum error correction and quantum algorithms. Linear reversible circuits, equivalent to circuits composed of CNOT gates, have important applications in classical computing. In…

Quantum Physics · Physics 2025-03-20 Mark Webster , Stergios Koutsioumpas , Dan E Browne

We prove new upper bounds on the tolerable level of noise in a quantum circuit. We consider circuits consisting of unitary k-qubit gates each of whose input wires is subject to depolarizing noise of strength p, as well as arbitrary…

Quantum Physics · Physics 2008-02-12 Julia Kempe , Oded Regev , Falk Unger , Ronald de Wolf

We study two-qubit circuits over the Clifford+CS gate set, which consists of the Clifford gates together with the controlled-phase gate CS=diag(1,1,1,i). The Clifford+CS gate set is universal for quantum computation and its elements can be…

Quantum Physics · Physics 2021-06-21 Andrew N. Glaudell , Neil J. Ross , Jacob M. Taylor

We present quantum circuits to implement an exhaustive key search for the Advanced Encryption Standard (AES) and analyze the quantum resources required to carry out such an attack. We consider the overall circuit size, the number of qubits,…

Quantum Physics · Physics 2015-12-17 Markus Grassl , Brandon Langenberg , Martin Roetteler , Rainer Steinwandt

Clifford group lies at the core of quantum computation -- it underlies quantum error correction, its elements can be used to perform magic state distillation and they form randomized benchmarking protocols, Clifford group is used to study…

Quantum Physics · Physics 2022-08-26 Sergey Bravyi , Joseph A. Latone , Dmitri Maslov

We consider the possibility of adding noise to a quantum circuit to make it efficiently simulatable classically. In previous works this approach has been used to derive upper bounds to fault tolerance thresholds - usually by identifying a…

Quantum Physics · Physics 2010-03-12 M. B. Plenio , S. Virmani

While implementing a quantum algorithm it is crucial to reduce the quantum resources, in order to obtain the desired computational advantage. For most fault-tolerant quantum error-correcting codes the cost of implementing the non-Clifford…

Quantum Physics · Physics 2023-02-10 Vlad Gheorghiu , Michele Mosca , Priyanka Mukhopadhyay

The paper discusses the asymptotic depth of a reversible circuit consisting of NOT, CNOT and 2-CNOT gates. Reversible circuit depth function $D(n, q)$ for a circuit implementing a transformation $f\colon \mathbb Z_2^n \to \mathbb Z_2^n$ is…

Emerging Technologies · Computer Science 2016-02-16 Dmitry V. Zakablukov

Quantum Approximate Optimization Algorithm (QAOA) is studied primarily to find approximate solutions to combinatorial optimization problems. For a graph with $n$ vertices and $m$ edges, a depth $p$ QAOA for the Max-cut problem requires…

We present improved quantum circuit for modular exponentiation of a constant, which is the most expensive operation in Shor's algorithm for integer factorization. While previous work mostly focuses on minimizing the number of qubits or the…

Quantum Physics · Physics 2023-11-28 Xia Liu , Huan Yang , Li Yang

Multi-controlled gates are fundamental components in the design of quantum algorithms, where efficient decompositions of these operators can enhance algorithm performance. The best asymptotic decomposition of an n-controlled X gate with one…

Quantum Physics · Physics 2024-07-09 Thiago Melo D. Azevedo , Jefferson D. S. Silva , Adenilton J. da Silva