English
Related papers

Related papers: Improving direct state measurements by using rebit…

200 papers

It has been recently shown that a state generated by a one-dimensional noisy quantum computer is well approximated by a matrix product operator with a finite bond dimension independent of the number of qubits. We show that full quantum…

Quantum Physics · Physics 2022-07-14 Alexander Lidiak , Casey Jameson , Zhen Qin , Gongguo Tang , Michael B. Wakin , Zhihui Zhu , Zhexuan Gong

Trace distance and infidelity (induced by square root fidelity), as basic measures of the closeness of quantum states, are commonly used in quantum state discrimination, certification, and tomography. However, the sample complexity for…

Quantum Physics · Physics 2024-10-29 Qisheng Wang , Zhicheng Zhang

High-dimensional quantum systems offer a new playground for quantum information applications due to their remarkable advantages such as higher capacity and noise resistance. We propose potentially practical schemes for remotely preparing…

Quantum Physics · Physics 2026-03-03 Jun-Hai Zhao , Si-Qi Du , Wen-Qiang Liu , Dong-Hong Zhao , Hai-Rui Wei

In order to faithfully detect the state of an individual two-state quantum system (qubit) realized using, for example, a trapped ion or atom, state selective scattering of resonance fluorescence is well established. The simplest way to read…

Quantum Physics · Physics 2015-04-23 Sabine Wölk , Christian Piltz , Theeraphot Sriarunothai , Christof Wunderlich

Encoding in a high-dimensional Hilbert space improves noise resilience in quantum information processing. This approach, however, may result in cross-mode coupling and detection complexities, thereby reducing quantum cryptography…

Quantum Physics · Physics 2025-10-30 Amit Kam , Kfir Sulimany , Shai Tsesses , Uzi Pereg

Quantum state tomography (QST) is a crucial tool for characterizing quantum states. However, QST becomes impractical for reconstructing multi-qubit density matrices since data sets and computational costs grow exponentially with qubit…

Quantum Physics · Physics 2026-04-02 Aniket Patel , Akshay Gaikwad , Tangyou Huang , Anton Frisk Kockum , Tahereh Abad

Reconstruction of density matrices is important in NMR quantum computing. An analysis is made for a 2-qubit system by using the error matrix method. It is found that the state tomography method determines well the parameters that are…

Quantum Physics · Physics 2009-11-06 G. L. Long , H. Y. Yan , Yang Sun

Quantum state tomography (QST) scales exponentially in both measurement and computational cost, making full reconstruction impractical for multi-qubit systems. Existing approaches attempt to reduce this complexity, but do not explicitly…

Quantum Physics · Physics 2026-04-24 Ayush Chambyal , Brijesh , Rakesh Sharma

We study the possibility of performing quantum state reconstruction from a measurement record that is obtained as a sequence of expectation values of a Hermitian operator evolving under repeated application of a single random unitary map,…

Quantum Physics · Physics 2010-04-29 Seth T. Merkel , Carlos A. Riofrio , Steven T. Flammia , Ivan H. Deutsch

Despite the significant progress in superconducting quantum computation over the past years, quantum state measurement still lags nearly an order of magnitude behind quantum gate operations in speed and fidelity. The main challenge is that…

In this paper, we present a general framework to solve a fundamental problem in Random Matrix Theory (RMT), i.e., the problem of describing the joint distribution of eigenvalues of the sum $\bsA+\bsB$ of two independent random Hermitian…

Quantum Physics · Physics 2019-11-14 Lin Zhang , Yixin Jiang , Junde Wu

Quantum state tomography (QST) remains the gold standard for benchmarking and verification of near-term quantum devices. While QST for a generic quantum many-body state requires an exponentially large amount of resources, most physical…

Quantum Physics · Physics 2024-08-15 Casey Jameson , Zhen Qin , Alireza Goldar , Michael B. Wakin , Zhihui Zhu , Zhexuan Gong

We introduce an approach for performing quantum state reconstruction on systems of $n$ qubits using a machine-learning-based reconstruction system trained exclusively on $m$ qubits, where $m\geq n$. This approach removes the necessity of…

In this paper we study the state determination for composite systems of two spatial qubits. We show, theoretically, that one can use the technique of quantum tomography to reconstruct the density matrixes of these systems. This tomographic…

Quantum Physics · Physics 2009-11-13 G. Lima , F. A. Torres-Ruiz , L. Neves , A. Delgado , C. Saavedra , S. Padua

When it comes to discriminating between two quantum states, trace distance is one of the well-known metrics used in quantum computation and quantum information theory. While there are several quantum algorithms for calculating the trace…

Quantum Physics · Physics 2026-04-08 Sanchita Ghosh , Anumita Mukhopadhyay , Anindita Bera , Prasenjit Deb , Shibdas Roy

Quantum state tomography (QST) is an essential technique for reconstructing the density matrix of an unknown quantum state from measurement data, crucial for quantum information processing. However, conventional QST requires an…

Quantum Physics · Physics 2025-06-05 Yoshiyuki Kakihara , Daisuke Yamamoto , Giacomo Marmorini

Quantum metrology explores quantum effects to improve the measurement accuracy of some physical quantities beyond the classical limit. However, due to the interaction between the system and the environment, the decoherence can significantly…

Quantum Physics · Physics 2024-05-07 Cheng-Ge Liu , Cong-Wei Lu , Na-Na Zhang , Qing Ai

It is known that a reliable geometric quantifier of discord-like correlations can be built by employing the so-called trace distance. This is used to measure how far the state under investigation is from the closest "classical-quantum" one.…

Quantum Physics · Physics 2014-01-24 F. Ciccarello , T. Tufarelli , V. Giovannetti

In the paper the Bayesian and the least squares methods of quantum state tomography are compared for a single qubit. The quality of the estimates are compared by computer simulation when the true state is either mixed or pure. The fidelity…

Quantum Physics · Physics 2007-05-23 Th. Baier , K. M. Hangos , A. Magyar , D. Petz

Extracting information from quantum devices has long been a crucial problem in the field of quantum mechanics. By performing elaborate measurements, quantum state tomography, an important and fundamental tool in quantum science and…

Quantum Physics · Physics 2022-06-24 Yu Wang , Keren Li
‹ Prev 1 3 4 5 6 7 10 Next ›