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As the building block in symmetric cryptography, designing Boolean functions satisfying multiple properties is an important problem in sequence ciphers, block ciphers, and hash functions. However, the search of $n$-variable Boolean…

Quantum Physics · Physics 2020-02-19 Feng Hu , Lucas Lamata , Mikel Sanz , Xi Chen , Xingyuan Chen , Chao Wang , Enrique Solano

Here we describe an approach for simulating electronic structure on quantum computers with significantly lower asymptotic complexity than prior work. The approach uses a real-space first-quantised representation of the molecular Hamiltonian…

In the near term, programming quantum computers will remain severely limited by low quantum volumes. Therefore, it is desirable to implement quantum circuits with the fewest resources possible. For the common Clifford+T circuits, most…

Computational Engineering, Finance, and Science · Computer Science 2023-11-16 Korbinian Staudacher , Tobias Guggemos , Sophia Grundner-Culemann , Wolfgang Gehrke

Progress in quantum hardware design is progressing toward machines of sufficient size to begin realizing quantum algorithms in disciplines such as encryption and physics. Quantum circuits for addition are crucial to realize many quantum…

Quantum Physics · Physics 2021-06-10 Himanshu Thapliyal , Edgard Muñoz-Coreas , Vladislav Khalus

We propose a fault-tolerant quantum computation scheme that is broadly applicable to quantum low-density parity-check (qLDPC) codes. The scheme achieves constant qubit overhead and a time overhead of $O(d^{a+o(1)})$ for any $[[n,k,d]]$…

Quantum Physics · Physics 2026-04-14 Guo Zhang , Yuanye Zhu , Ying Li

We describe methods for simulating general second-quantized Hamiltonians using the compact encoding, in which qubit states encode only the occupied modes in physical occupation number basis states. These methods apply to second-quantized…

Quantum Physics · Physics 2022-06-29 William M. Kirby , Sultana Hadi , Michael Kreshchuk , Peter J. Love

High-rate and large-distance quantum codes are expected to make fault-tolerant quantum computing more efficient, but most of them lack efficient fault-tolerant encoded-state preparation methods. We propose such a fault-tolerant encoder for…

Quantum Physics · Physics 2025-09-22 Naoyuki Kanomata , Hayato Goto

The Toffoli gate is a fundamental building block for quantum arithmetic and reversible logic, yet its efficient realization remains a major challenge in both near-term and fault-tolerant quantum architectures. Recent advances in dynamic…

Quantum Physics · Physics 2026-05-21 Abhoy Kole , Till Schnittka , Rolf Drechsler

Block encoding is a successful technique used in several powerful quantum algorithms. In this work we provide an explicit quantum circuit for block encoding a sparse matrix with a periodic diagonal structure. The proposed methodology is…

Quantum low-density parity-check (qLDPC) codes can achieve high encoding rates and good code distance scaling, providing a promising route to low-overhead fault-tolerant quantum computing. However, the long-range connectivity required to…

While Clifford operations are relatively easy to implement in fault-tolerant quantum computers,continuous rotation gates remain a significant bottleneck in typical quantum algorithms. In this work, we ask the question: "What is the most…

Quantum Physics · Physics 2026-05-06 Zhu Sun , Balint Koczor

Quantum low-density parity-check (qLDPC) codes are a promising construction for drastically reducing the overhead of fault-tolerant quantum computing (FTQC) architectures. However, all of the known hardware implementations of these codes…

We present a method for encoding second-quantized fermionic systems in qubits when the number of fermions is conserved, as in the electronic structure problem. When the number $F$ of fermions is much smaller than the number $M$ of modes,…

Quantum Physics · Physics 2022-06-09 William Kirby , Bryce Fuller , Charles Hadfield , Antonio Mezzacapo

Quantum circuits of arithmetic operations such as addition are needed to implement quantum algorithms in hardware. Quantum circuits based on Clifford+T gates are used as they can be made tolerant to noise. The tradeoff of gaining fault…

Quantum Physics · Physics 2020-04-07 Himanshu Thapliyal , Edgard Muñoz-Coreas , Vladislav Khalus

Block-encodings have become one of the most common oracle assumptions in the circuit model. I present an algorithm that uses von Neumann's measurement procedure to measure a phase, using time evolution on a block-encoded Hamiltonian as a…

Quantum Physics · Physics 2025-09-05 S. E. Skelton

We present a new scheme to perform noise resilient universal adiabatic quantum computation using two-body interactions. To achieve this, we introduce a new family of error detecting subsystem codes whose gauge generators and a set of their…

Quantum Physics · Physics 2019-11-05 Milad Marvian , Seth Lloyd

We develop new algorithms for Quantum Singular Value Transformation (QSVT), a unifying framework that encapsulates most known quantum algorithms and serves as the foundation for new ones. Existing implementations of QSVT rely on block…

Quantum Hamiltonian identification is important for characterizing the dynamics of quantum systems, calibrating quantum devices and achieving precise quantum control. In this paper, an effective two-step optimization (TSO) quantum…

Quantum Physics · Physics 2018-06-05 Yuanlong Wang , Daoyi Dong , Bo Qi , Jun Zhang , Ian R. Petersen , Hidehiro Yonezawa

We present a scalable framework for accurately modeling many-body interactions in surface-code quantum processor units (QPUs). Combining a concise diagrammatic formalism with high-precision numerical methods, our approach efficiently…

Quantum Physics · Physics 2025-07-09 Xuexin Xu , Kuljeet Kaur , Chloé Vignes , Mohammad H. Ansari , John M. Martinis

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