English
Related papers

Related papers: Practical Implementations of Twirl Operations

200 papers

We discuss and generalize multi-particle entanglement based on statistical correlations using Ursell-Mayer type of cluster coefficients. Cluster coefficients are used to distinguish different, independent entangled systems as well as those…

Quantum Physics · Physics 2009-11-15 Atul Kumar , Mangala Sunder Krishnan

We present an experimental scanning-based tomography approach for near-term quantum devices. The underlying method has previously been introduced in an ensemble-based NMR setting. Here we provide a tutorial-style explanation along with…

Quantum Physics · Physics 2024-12-04 Amit Devra , Niklas J. Glaser , Dennis Huber , Steffen J. Glaser

It has recently been shown that it is possible to represent the complete quantum state of any system as a phase-space quasi-probability distribution (Wigner function) [Phys Rev Lett 117, 180401]. Such functions take the form of expectation…

Quantum Physics · Physics 2017-08-16 R. P. Rundle , P. W. Mills , Todd Tilma , J. H. Samson , M. J. Everitt

This paper is an appendix to a previous paper: quant-ph/0101123 ``Relaxation Method for Calculating Quantum Entanglement", by Robert Tucci. For certain mixtures of Bell basis states, namely the Werner States, we use the theoretical…

Quantum Physics · Physics 2007-05-23 Robert R. Tucci

Quantum entanglement of pure states is usually quantified via the entanglement entropy, the von Neumann entropy of the reduced state. Entanglement entropy is closely related to entanglement distillation, a process for converting quantum…

Quantum Physics · Physics 2021-10-06 Tulja Varun Kondra , Chandan Datta , Alexander Streltsov

In tasks, where multipartite entanglement plays a central role, state purification is, due to inevitable noise, a crucial part of the procedure. We consider a scenario exploiting the multipartite entanglement in a straightforward…

Quantum Physics · Physics 2011-06-17 Marcus Huber , Martin Plesch

We propose a new avenue towards distillation of quantum entanglement that is implemented by directly passing the entangled qubits through a mode-matched filter. This approach can be applied to a common class of entanglement impurities…

Quantum Physics · Physics 2015-05-30 Yu-Ping Huang , Prem Kumar

Quantum mechanical entanglement is a resource for quantum computation, quantum teleportation, and quantum cryptography. The ability to quantify this resource correctly has thus become of great interest to those working in the field of…

Quantum Physics · Physics 2009-11-07 J. R. Gittings , A. J. Fisher

After a general introduction to nuclear magnetic resonance (NMR), we give the basics of implementing quantum algorithms. We describe how qubits are realized and controlled with RF pulses, their internal interactions, and gradient fields. A…

We study the performance of efficient quantum state tomography methods based on neural network quantum states using measured data from a two-photon experiment. Machine learning inspired variational methods provide a promising route towards…

Dynamical polarization of nuclear spin ensembles is of central importance for magnetic resonance studies, precision sensing and for applications in quantum information theory. Here we propose a scheme to generate long-lived singlet pairs in…

Quantum Physics · Physics 2017-04-06 Johannes N. Greiner , D. D. Bhaktavatsala Rao , Jörg Wrachtrup

This study explores robust entangled states described using the framework of discrete Wigner functions. Notably, these states are known to outperform the Bell state in measures of entanglement in the presence of non-Markovian noise. Our…

Quantum Physics · Physics 2025-05-01 Jai Lalita , Pavithran Iyer , Subhashish Banerjee

We use ultrafast optical pulses and coherent techniques to create spin entangled states of non-interacting electrons bound to donors (at least three) and at least two Mn2+ ions in a CdTe quantum well. Our method, relying on the exchange…

Quantum Physics · Physics 2009-11-07 J. Bao , A. V. Bragas , J. K. Furdyna , R. Merlin

Transfer of entanglement and information is studied for quantum teleportation of an unknown entangled state through noisy quantum channels. We find that the quantum entanglement of the unknown state can be lost during the teleportation even…

Quantum Physics · Physics 2009-01-23 Jinhyoung Lee , M. S. Kim

By building on the work in Kuzmak & Tkachuk, "Preparation of quantum states of two spin-$\frac{1}{2}$ particles in the form of the Schmidt decomposition", Physics Letters A, {\bf 378}, pp1469-1474, which outlined the control of the degree…

Quantum Physics · Physics 2015-02-19 Roderick Vance

We have studied transition metal clusters from a quantum information theory perspective using the density-matrix renormalization group (DMRG) method. We demonstrate the competition between entanglement and interaction localization. We also…

Quantum Physics · Physics 2015-05-19 G. Barcza , Ö. Legeza , K. H. Marti , M. Reiher

We investigate analytically and numerically the Multiple Quantum (MQ) NMR dynamics in systems of nuclear spins 1/2 coupled by the dipole-dipole interactions in the case of the dipolar ordered initial state. We suggest two different methods…

Other Condensed Matter · Physics 2009-11-13 S. I. Doronin , E. B. Fel'dman , E. I. Kuznetsova , G. B. Furman , S. D. Goren

Problems in realization of silicon-based solid-state NMR quantum computer with ensemble addressing to qubits are considered. It is presented the extension of Kane's scheme to ensemble approach version with strip gates. For the…

Quantum Physics · Physics 2007-05-23 A. A. Kokin , K. A. Valiev

Understanding quantum systems is of significant importance for assessing the performance of quantum hardware and software, as well as exploring quantum control and quantum sensing. An efficient representation of quantum states enables…

Quantum Physics · Physics 2024-10-10 Yuchen Guo , Shuo Yang

We propose two probabilistic entanglement concentration schemes for a single copy of two-mode squeezed vacuum state. The first scheme is based on the off-resonant interaction of a Rydberg atom with the cavity field while the second setup…

Quantum Physics · Physics 2012-08-27 Jaromir Fiurasek , Ladislav Mista, , Radim Filip