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Related papers: Magnetic noise in macroscopic quantum spatial supe…

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A single-spin qubit placed near the surface of a conductor acquires an additional contribution to its $1/T_1$ relaxation rate due to magnetic noise created by electric current fluctuations in the material. We analyze this technique as a…

Vacuum fluctuations can obscure the detection signal of the measurement of the smallest quantum objects like single particles seemingly implying a fundamental limit to measurement accuracy. However, as we show relativistic invariance…

Quantum Physics · Physics 2022-06-07 Adam Bednorz , Wolfgang Belzig

A minimally invasive technique is proposed for detecting the differential spin conductance and spin current noise across a junction between two quantum magnets using a high-quality microwave resonator coupled to a transmission line which is…

Mesoscale and Nanoscale Physics · Physics 2019-05-27 Joshua Aftergood , Mircea Trif , So Takei

In s-wave superconductors with a small concentration of magnetic impurities, the only electronic excitations that remain available at low temperatures are the excitations of the system of localized spins. We discuss a new mechanism of…

Superconductivity · Physics 2025-12-12 Shiang-Bin Chiu , Anton Andreev , Alexander Burin , Boris Z. Spivak

Matter-wave interferometry with increasingly larger masses could pave the way to understanding the nature of wavefunction collapse, the quantum to classical transition or even how an object in a spatial superposition interacts with its…

Quantum Physics · Physics 2024-05-09 Jakub Wardak , Tiberius Georgescu , Giulio Gasbarri , Alessio Belenchia , Hendrik Ulbricht

The small mass and high coherence of nanomechanical resonators render them the ultimate force probe, with applications ranging from biosensing and magnetic resonance force microscopy, to quantum optomechanics. A notorious challenge in these…

Quantum Physics · Physics 2017-07-18 Yeghishe Tsaturyan , Andreas Barg , Eugene S. Polzik , Albert Schliesser

We propose and study a realistic model for the decoherence of topological qubits, based on Majorana fermions in one-dimensional topological superconductors. The source of decoherence is the fluctuating charge on a capacitively coupled gate,…

Mesoscale and Nanoscale Physics · Physics 2012-08-14 Manuel J. Schmidt , Diego Rainis , Daniel Loss

We compute the entanglement entropy, mutual information and quantum discord of the Cosmic Microwave Background (CMB) fluctuations in real space. To that end, we first show that measurements of these fluctuations at two distinct spatial…

General Relativity and Quantum Cosmology · Physics 2023-06-30 Jerome Martin , Vincent Vennin

We show how the partition function of a network of parallel superconducting wires weakly coupled together by the proximity effect, subjected a vector potential along the wires can be mapped onto N-distinguishable two dimensional…

Superconductivity · Physics 2008-06-24 Kohjiro Kobayashi , David Stroud

The existence of vacuum fluctuations is one of the most important predictions of modern quantum field theory. In the vacuum state, fluctuations occurring at different frequencies are uncorrelated. However, if a parameter in the Lagrangian…

Mesoscale and Nanoscale Physics · Physics 2018-12-20 Pasi Lähteenmäki , Gheorghe Sorin Paraoanu , Juha Hassel , Pertti J. Hakonen

We investigate the magnetic thermal noise in magnetic nanowires with and without a domain wall by employing micromagnetic simulations. The magnetic thermal noise due to random thermal fluctuation fields gives important physical quantities…

Materials Science · Physics 2015-05-19 Jungbum Yoon , Chun-Yeol You , Younghun Jo , Seung-Young Park , Myung-Hwa Jung

Under ideal conditions, quantum metrology promises a precision gain over classical techniques scaling quadratically with the number of probe particles. At the same time, no-go results have shown that generic, uncorrelated noise limits the…

Quantum Physics · Physics 2017-07-13 J. B. Brask , R. Chaves , J. Kolodynski

Slow fluctuations of a qubit frequency are one of the major problems faced by quantum computers. To understand their origin it is necessary to go beyond the analysis of their spectra. We show that characteristic features of the fluctuations…

Quantum Physics · Physics 2024-01-11 Filip Wudarski , Yaxing Zhang , M. I. Dykman

Quantum spin fluctuations provide a unique way to study spin dynamics without system perturbation. Here we put forward an optical resonance shift spin noise spectroscopy as a powerful tool to measure the spin noise of various systems from…

Mesoscale and Nanoscale Physics · Physics 2020-07-01 D. S. Smirnov , K. V. Kavokin

By scattering theory we show that spin current noise in normal electric conductors in contact with nanoscale ferromagnets increases the magnetization noise by means of a fluctuating spin-transfer torque. Johnson-Nyquist noise in the spin…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 Jorn Foros , Arne Brataas , Yaroslav Tserkovnyak , Gerrit E. W. Bauer

The quantum measurement problems are revisited from a new perspective. One of the main ideas of this work is that the basic entities of our world are various types of particles, elementary or composite. It follows that each elementary…

Quantum Physics · Physics 2022-09-07 Kenichi Konishi

Space--time can be understood as some kind of space--time foam of fluctuating bubbles or loops which are expected to be an outcome of a theory of quantum gravity. One recently discussed model for this kind of space--time fluctuations is the…

General Relativity and Quantum Cosmology · Physics 2011-06-02 Ertan Göklü , Claus Lämmerzahl

The ability to live in coherent superpositions is a signature trait of quantum systems and constitutes an irreplaceable resource for quantum-enhanced technologies. However, decoherence effects usually destroy quantum superpositions. It has…

Recent inelastic neutron scattering (INS) experiments on La$_{2-x}$Sr$_x$CuO$_4$ have established the existence of a {\it magnetic coherence effect}, i.e., strong frequency and momentum dependent changes of the spin susceptibility,…

Superconductivity · Physics 2009-10-31 Dirk K. Morr , David Pines

The superposition principle is one of the main tenets of quantum mechanics. Despite its counter-intuitiveness, it has been experimentally verified using electrons, photons, atoms, and molecules. However, a similar experimental demonstration…

Quantum Physics · Physics 2020-02-25 A T M Anishur Rahman