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Related papers: Stabilizers may be poor bounds for fidelities

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In the theory of operator quantum error correction (OQEC), the notion of correctability is defined under the assumption that states are perfectly initialized inside a particular subspace, a factor of which (a subsystem) contains the…

Quantum Physics · Physics 2008-08-24 Ognyan Oreshkov

Estimating the state preparation fidelity of highly entangled states on noisy intermediate-scale quantum (NISQ) devices is important for benchmarking and application considerations. Unfortunately, exact fidelity measurements quickly become…

Quantum Physics · Physics 2025-01-29 Shamminuj Aktar , Andreas Bärtschi , Abdel-Hameed A. Badawy , Stephan Eidenbenz

We pose the question whether the asymptotic equivalence between quantum cloning and quantum state estimation, valid at single-copy level, still holds when all the copies are examined jointly. For an N-to-M cloner, we consider the overall…

Quantum Physics · Physics 2014-04-07 Yuxiang Yang , Giulio Chiribella

We consider the optimal cloning of quantum coherent states with single-clone and joint fidelity as figures of merit. Both optimal fidelities are attained for phase space translation covariant cloners. Remarkably, the joint fidelity is…

Quantum Physics · Physics 2007-05-23 N. J. Cerf , O. Krueger , P. Navez , R. F. Werner , M. M. Wolf

The Knill-Laflamme (KL) conditions distinguish exact quantum error correction codes, and it has played a critical role in the discovery of state-of-the-art codes. However, the family of exact codes is a very restrictive one and does not…

Quantum Physics · Physics 2024-06-21 Guo Zheng , Wenhao He , Gideon Lee , Liang Jiang

With the significance of continuous-variable quantum computing increasing thanks to the achievements of light-based quantum hardware, making it available to learner audiences outside physics has been an important yet seldom-tackled…

Quantum Physics · Physics 2025-07-10 Richard A. Wolf , Pavithran Iyer

In this paper we address the problem of optimal reconstruction of a quantum state from the result of a single measurement when the original quantum state is known to be a member of some specified set. A suitable figure of merit for this…

Quantum Physics · Physics 2007-05-23 Kieran Hunter , Erika Andersson , Claire R. Gilson , Stephen M. Barnett

One of the many interesting features of quantum nonlocality is that the states of a multipartite quantum system cannot always be distinguished as well by local measurements as they can when all quantum measurements are allowed. In this…

Quantum Physics · Physics 2013-11-14 Somshubhro Bandyopadhyay , Michael Nathanson

We present the coherent states of the harmonic oscillator in the framework of the generalized (gravitational) uncertainty principle (GUP). This form of GUP is consistent with various theories of quantum gravity such as string theory, loop…

High Energy Physics - Theory · Physics 2013-03-04 Pouria Pedram

State-dependent cloning machines that have so far been considered either deterministically copy a set of states approximately, or probablistically copy them exactly. In considering the case of two equiprobable pure states, we derive the…

Quantum Physics · Physics 2009-10-31 Anthony Chefles , Stephen M. Barnett

Magic states can be used as a resource to circumvent the restrictions due to stabilizer-preserving operations, and magic-state conversion has not been studied in the single-copy regime thus far. Here we solve the question of whether a…

Quantum Physics · Physics 2018-06-22 Mehdi Ahmadi , Hoan Bui Dang , Gilad Gour , Barry C. Sanders

We consider the task of performing shadow tomography of a logical subsystem defined via the Gottesman-Kitaev-Preskill (GKP) error correcting code. Our protocol does not require the input state to be a code state but is implemented by…

Quantum Physics · Physics 2026-01-29 Jonathan Conrad , Jens Eisert , Steven T. Flammia

Magic state distillation is an important primitive in fault-tolerant quantum computation. The magic states are pure non-stabilizer states which can be distilled from certain mixed non-stabilizer states via Clifford group operations alone.…

Quantum Physics · Physics 2013-05-29 Earl T. Campbell , Dan E. Browne

In this paper dynamics and quantum mechanical coherent states of a simple harmonic oscillator are considered in the framework of Generalized Uncertainty Principle(GUP). Equations of motion for simple harmonic oscillator are derived and some…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Kourosh Nozari , Tahereh Azizi

Bosonic quantum error correction codes encode logical qubits in the Hilbert space of one or multiple harmonic oscillators. A prominent class of bosonic codes is that of Gottesman-Kitaev-Preskill (GKP) codes of which implementations have…

Quantum Physics · Physics 2025-02-28 Leon H. Bohnmann , David F. Locher , Johannes Zeiher , Markus Müller

We present the first detailed simulation of a measurement based quantum computation based on Gottesman-Kitaev-Preskill (GKP) qubits within a quad-rail lattice (QRL) cluster state involving over 100 GKP modes. This was enabled by the…

An adaptive method for quantum state fidelity estimation in bipartite higher dimensional systems is established. This method employs state verifier operators which are constructed by local POVM operators and adapted to the measurement…

Quantum Physics · Physics 2020-09-17 Jun-Yi Wu

It is shown that by switching a specific time-dependent interaction between a harmonic oscillator and a transmission line (a waveguide, an optical fiber, etc.) the quantum state of the oscillator can be transferred into that of another…

Quantum Physics · Physics 2007-05-23 K. Jahne , B. Yurke , U. Gavish

We show that the quantum measurement known as the pretty good measurement can be used to identify an unknown quantum state picked from any set of $n$ mixed states that have pairwise fidelities upper-bounded by a constant below 1, given…

Quantum Physics · Physics 2019-11-11 Ashley Montanaro

The integration of diverse quantum resources and the exploitation of more degrees of freedom provide key operational flexibility for universal fault-tolerant quantum computation. In this work, we propose a flexible…

Quantum Physics · Physics 2026-03-20 Peilin Du , Jing Zhang , Tiancai Zhang , Rongguo Yang , Kui Liu , Jiangrui Gao