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The Eastin-Knill theorem states that no quantum error correcting code can have a universal set of transversal gates. For CSS codes that can implement Clifford gates transversally it suffices to provide one additional non-Clifford gate, such…

Quantum Physics · Physics 2021-11-15 Christophe Piveteau , David Sutter , Sergey Bravyi , Jay M. Gambetta , Kristan Temme

In this work we establish lower bounds on the size of Clifford circuits that measure a family of commuting Pauli operators. Our bounds depend on the interplay between a pair of graphs: the Tanner graph of the set of measured Pauli…

Quantum Physics · Physics 2021-09-30 Nicolas Delfosse , Michael E. Beverland , Maxime A. Tremblay

We study parallel fault-tolerant quantum computing for families of homological quantum low-density parity-check (LDPC) codes defined on 3-manifolds with constant or almost-constant encoding rate. We derive generic formula for a transversal…

Quantum Physics · Physics 2025-12-16 Guanyu Zhu , Shehryar Sikander , Elia Portnoy , Andrew W. Cross , Benjamin J. Brown

In this paper, the problem of constructing an efficient quantum circuit for the implementation of an arbitrary quantum computation is addressed. To this end, a basic block based on the cosine-sine decomposition method is suggested which…

Quantum Physics · Physics 2012-09-04 Mehdi Saeedi , Mona Arabzadeh , Morteza Saheb Zamani , Mehdi Sedighi

This paper introduces a framework for constructing Calderbank-Shor-Steane (CSS) codes that support fault-tolerant logical transversal $Z$-rotations. Using this framework, we obtain asymptotically good CSS codes that fault-tolerantly realize…

Quantum Physics · Physics 2026-04-08 K. Sai Mineesh Reddy , Navin Kashyap

We simulate the logical Hadamard gate in the surface code under a circuit-level noise model, compiling it to a physical circuit on square-grid connectivity hardware. Our paper is the first to do this for a logical unitary gate on a quantum…

In fault-tolerant quantum computing with the surface code, non-Clifford gates are crucial for universal computation. However, implementing these gates using methods like magic state distillation and code switching requires significant…

Quantum Physics · Physics 2025-07-02 Sheng-Jie Huang , Yanzhu Chen

In this paper we study single qutrit circuits consisting of words over the Clifford$+D$ cyclotomic gate set, where $D=\text{diag}(\pm\xi^{a},\pm\xi^{b},\pm\xi^{c})$, $\xi$ is a primitive $9$-th root of unity and $a,b,c$ are integers. We…

Quantum Physics · Physics 2025-03-05 Amolak Ratan Kalra , Michele Mosca , Dinesh Valluri

We realize a suite of logical operations on a distance-two logical qubit stabilized using repeated error detection cycles. Logical operations include initialization into arbitrary states, measurement in the cardinal bases of the Bloch…

Transversal gates play a crucial role in suppressing error propagation in fault-tolerant quantum computation, yet they are intrinsically constrained: any nontrivial code encoding a single logical qubit admits only a finite subgroup of…

Quantum Physics · Physics 2025-04-30 Chao Zhang , Zipeng Wu , Shilin Huang , Bei Zeng

In this article, we present a dynamical scheme to obtain a reconfigurable noise-aided logic gate, that yields all six fundamental 2-input logic operations, including the XOR operation. The setup consists of two coupled bistable subsystems…

Adaptation and Self-Organizing Systems · Physics 2022-01-20 Manaoj Aravind , P. Parmananda , Sudeshna Sinha

We propose a systematic and efficient quantum circuit composed solely of Clifford gates for simulating the ground state of the surface code model. This approach yields the ground state of the toric code in $\lceil…

Strongly Correlated Electrons · Physics 2024-03-13 Penghua Chen , Bowen Yan , Shawn X. Cui

In this work we improve the runtime of recent classical algorithms for strong simulation of quantum circuits composed of Clifford and T gates. The improvement is obtained by establishing a new upper bound on the stabilizer rank of $m$…

Quantum Physics · Physics 2021-12-22 Hammam Qassim , Hakop Pashayan , David Gosset

We show how to perform scalable fault-tolerant non-Clifford gates in two dimensions by introducing domain walls between the surface code and a non-Abelian topological code whose codespace is stabilized by Clifford operators. We formulate a…

We report a resource estimation pipeline that explicitly compiles quantum circuits expressed using the Clifford+T gate set into a surface code lattice surgery instruction set. The cadence of magic state requests from the compiled circuit…

Quantum Physics · Physics 2024-10-28 Tyler LeBlond , Christopher Dean , George Watkins , Ryan S. Bennink

When visualised as an operation on the Bloch sphere, the qubit "pi-over-eight" gate corresponds to one-eighth of a complete rotation about the vertical axis. This simple gate often plays an important role in quantum information theory,…

Quantum Physics · Physics 2012-08-17 Mark Howard , Jiri Vala

Magic State Distillation (MSD) has been a research focus for fault-tolerant quantum computing due to the need for non-Clifford resource in gaining quantum advantage. Although many of the MSD protocols so far are based on stabilizer codes…

Quantum Physics · Physics 2025-09-23 Yunzhe Zheng , Dong E. Liu

A fundamental problem of fault-tolerant quantum computation with quantum low-density parity-check (qLDPC) codes is the tradeoff between connectivity and universality. It is widely believed that in order to perform native logical…

Quantum Physics · Physics 2026-01-13 Guanyu Zhu , Ryohei Kobayashi , Po-Shen Hsin

Prior work has shown that there exists a relation problem which can be solved with certainty by a constant-depth quantum circuit composed of geometrically local gates in two dimensions, but cannot be solved with high probability by any…

Quantum Physics · Physics 2020-07-14 Sergey Bravyi , David Gosset , Robert Koenig , Marco Tomamichel

We propose several optimizations of the CliNR partial error correction scheme which implements Clifford circuits by consuming a resource state. Errors are corrected by measuring a sequence of Pauli operators that we refer to as the…

Quantum Physics · Physics 2025-08-27 Edwin Tham , Nicolas Delfosse