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Randomized saturation designs are a family of designs which assign a possibly different treatment proportion to each cluster of a population at random. As a result, they generalize the well-known (stratified) completely randomized designs…

Methodology · Statistics 2022-03-21 Chencheng Cai , Jean Pouget-Abadie , Edoardo M. Airoldi

Quantum complexity is a measure of the minimal number of elementary operations required to approximately prepare a given state or unitary channel. Recently, this concept has found applications beyond quantum computing -- in studying the…

Quantum Physics · Physics 2025-01-22 Michał Oszmaniec , Marcin Kotowski , Michał Horodecki , Nicholas Hunter-Jones

We define a map from an arbitrary quantum circuit to a local Hamiltonian whose ground state encodes the quantum computation. All previous maps relied on the Feynman-Kitaev construction, which introduces an ancillary `clock register' to…

Quantum Physics · Physics 2024-08-08 Anurag Anshu , Nikolas P. Breuckmann , Quynh T. Nguyen

We use a random search technique to find quantum gate sequences that implement perfect quantum state preparation or unitary operator synthesis with arbitrary targets. This approach is based on the recent discovery that there is a large…

Quantum Physics · Physics 2024-10-25 Sahel Ashhab , Fumiki Yoshihara , Miwako Tsuji , Mitsuhisa Sato , Kouichi Semba

For the kinetic energy of 1d model finite systems the leading corrections to local approximations as a functional of the potential are derived using semiclassical methods. The corrections are simple, non-local functionals of the potential.…

Other Condensed Matter · Physics 2010-06-25 Attila Cangi , Donghyung Lee , Peter Elliott , Kieron Burke

Quantum circuits with local particle number conservation (LPNC) restrict the quantum computation to a subspace of the Hilbert space of the qubit register. In a noiseless or fault-tolerant quantum computation, such quantities are preserved.…

Quantum Physics · Physics 2021-04-21 Michael Streif , Martin Leib , Filip Wudarski , Eleanor Rieffel , Zhihui Wang

We prove a number of structural and representation-theoretic results on linearly reductive quantum groups, i.e. objects dual to that of cosemisimple Hopf algebras: (a) a closed normal quantum subgroup is automatically linearly reductive if…

Quantum Algebra · Mathematics 2021-10-19 Alexandru Chirvasitu

Quantum error correction and symmetry arise in many areas of physics, including many-body systems, metrology in the presence of noise, fault-tolerant computation, and holographic quantum gravity. Here we study the compatibility of these two…

Quantum computers have now appeared in our society and are utilized for the investigation of science and engineering. At present, they have been built as intermediate-size computers containing about fifty qubits and are weak against noise…

Quantum Physics · Physics 2020-12-07 Yusuke Hama

Executing a logical quantum circuit fault-tolerantly incurs a large spacetime overhead. Recent work has proposed and investigated phantom codes, defined by the property that every in-block logical $\mathrm{CNOT}$ circuit can be implemented…

Quantum Physics · Physics 2026-04-17 Arthur S. Morris , Daniel Malz

The generation of $k$-designs (pseudorandom distributions that emulate the Haar measure up to $k$ moments) with local quantum circuit ensembles is a problem of fundamental importance in quantum information and physics. Despite the extensive…

Quantum Physics · Physics 2024-12-31 Zimu Li , Han Zheng , Junyu Liu , Liang Jiang , Zi-Wen Liu

In [1], Collins et al. showed that the quantum entropy of random graph states satisfies the so-called area law as the local dimension tends to be large. In this paper, we continue to study the fluctuation of the convergence and thus prove…

Quantum Physics · Physics 2024-01-12 Zhi Yin , Liang Zhao

Projective measurements with high quantum efficiency is often assumed to be required for efficient circuit based quantum computing. We argue that this is not the case and show that this fact has actually be known previously though not…

Quantum Physics · Physics 2015-03-17 A. P. Lund

Intrinsic randomness is generated when a quantum state is measured in any basis in which it is not diagonal. In an adversarial scenario, we quantify this randomness by the probability that a correlated eavesdropper could correctly guess the…

Quantum Physics · Physics 2026-02-19 Fionnuala Curran

Here we focus on the measurement induced nonlocality and present a redefinition in terms of the skew information subject to a broken observable. It is shown that the obtained quantity possesses an obvious operational meaning, can tackle the…

Quantum Physics · Physics 2019-03-19 Li-qiang Zhang , Ting-ting Ma , Chang-shui Yu

In ideal quantum circuits, qubits are tacitly assumed to be uniformly fabricated and operated by prescribed signals. In reality, however, we must cope with different control signals to adjust individual qubits, which requires a large…

Quantum Physics · Physics 2019-10-15 Tetsufumi Tanamoto , Masahito Ueda

Recent work [M. J. Gullans et al., Physical Review X, 11(3):031066 (2021)] has shown that quantum error correcting codes defined by random Clifford encoding circuits can achieve a non-zero encoding rate in correcting errors even if the…

Quantum Physics · Physics 2024-07-18 Andrew S. Darmawan , Yoshifumi Nakata , Shiro Tamiya , Hayata Yamasaki

We have generalized the well-known statement that the Clifford group is a unitary 3-design into symmetric cases by extending the notion of unitary design. Concretely, we have proven that a symmetric Clifford group is a symmetric unitary…

Quantum Physics · Physics 2024-05-27 Yosuke Mitsuhashi , Nobuyuki Yoshioka

Noisy intermediate-scale quantum processors have produced a quantum computation revolution in recent times. However, to make further advances new strategies to overcome the error rate growth are needed. One possible way out is dividing…

Quantum Physics · Physics 2025-01-20 J. Montes , F. Borondo , Gabriel G. Carlo

We show that a subset of the basis for the irreducible representations of a tensor-product SU(2) rotation forms a covariant approximate quantum error-correcting code with transversal U(1) logical gates. Generalizing previous work on…

Quantum Physics · Physics 2025-09-25 Cheng-Ju Lin , Zi-Wen Liu , Victor V. Albert , Alexey V. Gorshkov