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Related papers: Disentangling magic states with classically simula…

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Let G(A,B) denote the 2-qubit gate which acts as the 1-qubit SU(2) gates A and B in the even and odd parity subspaces respectively, of two qubits. Using a Clifford algebra formalism we show that arbitrary uniform families of circuits of…

Quantum Physics · Physics 2008-11-19 Richard Jozsa , Akimasa Miyake

One of the key challenges in quantum information is coherently manipulating the quantum state. However, it is an outstanding question whether control can be realized with low error. Only gates from the Clifford group -- containing $\pi$,…

We introduce a complete equational theory for the fragment of quantum circuits generated by the real Clifford gates plus the two-qubit controlled-Hadamard gate. That is, we give a simple set of equalities between circuits of this fragment,…

Quantum Physics · Physics 2026-02-09 Alexandre Clément

We present an infinite family of protocols to distill magic states for $T$-gates that has a low space overhead and uses an asymptotic number of input magic states to achieve a given target error that is conjectured to be optimal. The space…

Quantum Physics · Physics 2017-10-04 Jeongwan Haah , Matthew B. Hastings , D. Poulin , D. Wecker

The entanglement level statistics of a quantum state have recently been proposed to be a signature of universality in the underlying quantum circuit. This is a consequence of level repulsion in the entanglement spectra being tied to the…

Quantum Physics · Physics 2024-08-08 Andrew M. Projansky , Joshuah T. Heath , James D. Whitfield

In this paper, we introduce a class of highly entangled real quantum states that cannot be approximated by circuits with $\log$-many non-Clifford gates and prove that Bell sampling enables efficient cross-device verification (or distributed…

Quantum Physics · Physics 2025-08-07 Janek Denzler , Santiago Varona , Tommaso Guaita , Jose Carrasco

We present two classical algorithms for the simulation of universal quantum circuits on $n$ qubits constructed from $c$ instances of Clifford gates and $t$ arbitrary-angle $Z$-rotation gates such as $T$ gates. Our algorithms complement each…

Quantum Physics · Physics 2022-06-27 Hakop Pashayan , Oliver Reardon-Smith , Kamil Korzekwa , Stephen D. Bartlett

We search for efficient disentanglers on random Clifford circuits of two-qubit gates arranged in a brick-wall pattern, using the proximal policy optimization (PPO) algorithm \cite{schulman2017proximalpolicyoptimizationalgorithms}.…

Quantum Physics · Physics 2024-11-18 Ning Bao , Keiichiro Furuya , Gun Suer

We provide a new approach for compiling quantum simulation circuits that appear in Trotter, qDRIFT and multi-product formulas to Clifford and non-Clifford operations that can reduce the number of non-Clifford operations by a factor of up to…

Quantum Physics · Physics 2023-05-09 Priyanka Mukhopadhyay , Nathan Wiebe , Hong Tao Zhang

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

Quantum magic, quantified by nonstabilizerness, measures departures from stabilizer structure and underlies potential quantum speedups. We introduce an efficient classical framework for computing stabilizer R\'enyi entropies and stabilizer…

Quantum Physics · Physics 2026-04-21 Zhenyu Xiao , Shinsei Ryu

We show that qubit stabilizer states can be represented by non-negative quasi-probability distributions associated with a Wigner-Weyl-Moyal formalism where Clifford gates are positive state-independent maps. This is accomplished by…

Quantum Physics · Physics 2018-01-03 Lucas Kocia , Peter Love

We introduce the magic hierarchy, a quantum circuit model that alternates between arbitrary-sized Clifford circuits and constant-depth circuits with two-qubit gates ($\textsf{QNC}^0$). This model unifies existing circuit models, such as…

Quantum Physics · Physics 2025-08-29 Natalie Parham

In fault-tolerant quantum circuit synthesis, T gates supplied via magic states dominate space-time cost, while Clifford gates incur negligible overhead. Conventional flows minimize AND count in an {XOR, AND, NOT} basis as a proxy for T,…

Quantum Physics · Physics 2026-05-18 Hanyu Wang , Mingfei Yu , Xinrui Wu , Jason Cong

We show how looped pipeline architectures - which use short-range shuttling of physical qubits to achieve a finite amount of non-local connectivity - can be used to efficiently implement the fault-tolerant non-Clifford gate between 2D…

Quantum Physics · Physics 2025-02-17 Thomas R. Scruby , Kae Nemoto , Zhenyu Cai

We propose a new family of error detecting stabilizer codes with an encoding rate 1/3 that permit a transversal implementation of the pi/8-rotation $T$ on all logical qubits. The new codes are used to construct protocols for distilling…

Quantum Physics · Physics 2012-11-30 Sergey Bravyi , Jeongwan Haah

We introduce magic-augmented Clifford circuits -- architectures in which Clifford circuits are preceded and/or followed by constant-depth circuits of non-Clifford (``magic") gates -- as a resource-efficient way to realize approximate…

Quantum Physics · Physics 2026-03-09 Yuzhen Zhang , Sagar Vijay , Yingfei Gu , Yimu Bao

A cluster state is a strongly entangled state, which is a source of measurement-based quantum computation. It is generated by applying controlled-Z (CZ) gates to the state $\left\vert ++\cdots +\right\rangle $. It is protected by the…

Quantum Physics · Physics 2026-02-25 Motohiko Ezawa

Though Cliffords and matchgates are both examples of classically simulable circuits, they are considered simulable for different reasons. The celebrated Gottesman-Knill explains the simulability Cliffords, and the efficient simulability of…

Quantum Physics · Physics 2025-03-26 Andrew M. Projansky , Jason Necaise , James D. Whitfield

Magic state distillation (MSD) is a cornerstone of fault-tolerant quantum computing, enabling non-Clifford gates via state injection into stabilizer circuits. However, the substantial overhead of current MSD protocols remains a major…

Quantum Physics · Physics 2026-05-26 Muhammad Erew , Moshe Goldstein , Yaron Oz , Haim Suchowski