The Vienna Nuclear Demagnetization Refrigerator

Nguyen, Dung; Sidorenko, A.; Mûller, Martín; Paschen, S.; Waard, A. de; Frossati, G.

doi:10.1088/1742-6596/400/5/052024

Cited by 5 publications

(6 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We have developed, and implemented in a nuclear demagnetization cryostat 31 , a setup for high-resolution electrical resistivity measurements to temperatures well below 1 mK (see Methods), and used it to measure state-of-the-art YbRh 2 Si 2 single crystals 17,32 . To assess the previously discussed 33 role of Yb nuclear moments, in addition to samples with natural abundance Yb (containing 14.2% 171 Yb with a nuclear moment I = 1/2 and 16.1% 173 Yb with a nuclear moment I = 5/2) 32 , we also studied 174 YbRh 2 Si 2 , which is free of nuclear Yb moments 17 .…”

Section: Resultsmentioning

confidence: 99%

“…Refrigerator and thermometry. All measurements were carried out in the Vienna nuclear demagnetization refrigerator 31 . We use resistance thermometry (Pt resistance thermometers Pt-1000, RuO 2 thermometers, and sliced Speer carbon resistance thermometers) for temperatures above 10 mK and magnetic thermometry (CMN, pulsed Pt-NMR thermometers, via the pulsed nuclear magnetic resonance of 195 Pt nuclei) for temperature below 20 mK.…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Superconductivity in an extreme strange metal

et al. 2021

View full text Add to dashboard Cite

Some of the highest-transition-temperature superconductors across various materials classes exhibit linear-in-temperature ‘strange metal’ or ‘Planckian’ electrical resistivities in their normal state. It is thus believed by many that this behavior holds the key to unlock the secrets of high-temperature superconductivity. However, these materials typically display complex phase diagrams governed by various competing energy scales, making an unambiguous identification of the physics at play difficult. Here we use electrical resistivity measurements into the micro-Kelvin regime to discover superconductivity condensing out of an extreme strange metal state—with linear resistivity over 3.5 orders of magnitude in temperature. We propose that the Cooper pairing is mediated by the modes associated with a recently evidenced dynamical charge localization–delocalization transition, a mechanism that may well be pertinent also in other strange metal superconductors.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Superconductivity in an extreme strange metal

et al. 2021

View full text Add to dashboard Cite

show abstract

“…From an experimental perspective, we see that T ∼0.1 mK can not be reached with standard dilution refrigerators (which typically reaches 10 mK and hardly below). However such temperatures could be reached by employing advanced techniques such as adiabatic nuclear demagnetization refrigerators [47]. Alternatively, one could think of using GHz oscillators, for which the nonlocality properties discussed here would be visible at higher temperatures.…”

Section: Tripartite Nonlocality Versus Tripartite Entanglementmentioning

confidence: 99%

More nonlocality with less entanglement in a tripartite atom‐optomechanical system

Zhang

Xuereb

et al. 2014

Annalen der Physik

View full text Add to dashboard Cite

We study quantum effects in hybrid atomic optomechanics in a system comprising a cloud of atoms and a mobile mirror mediated by a single-mode cavity. Tripartite nonlocality is observed in the atom-light-mirror system, as demonstrated by the violation of the Mermin-Klyshko (MK) inequality. It has been shown [C. Genes, et al., PRA 77, 050307 (R) (2008)] that tripartite entanglement is optimized when the cavity is resonant with the anti-Stokes sideband of the driving laser and the atomic frequency matches the Stokes one. However, we show that this is not the case for the nonlocality. The MK function achieves minima when the atoms are resonant with both the Stokes and anti-Stokes sidebands, and unexpectedly, we find violation of the MK inequality only in a parameter region where entanglement is far from being maximum. A negative relation exists between nonlocality and entanglement with consideration of the possibility of bipartite nonlocality in the violation of the MK inequality. We also study the non-classicality of the mirror by post-selected measurements, e.g. Geiger-like detection, on the cavity and/or the atoms. We show that with feasible parameters Geiger-like detection on the atoms can effectively induce mechanical non-classicality. PACS numbers:The lack of observation of quantum effects at the macroscopic scale reinforces the conjecture that macroscopic objects are governed by classical physics, while the microscopic world is ruled by quantum mechanics. However, quantum mechanics intrinsically shows no limitation to describe largescale/massive systems [1]. Preparing macroscopic quantum states is of vital importance for understanding fundamental issues in quantum mechanics, such as decoherence and the quantum-to-classical transition [2], collapse models of the wave function [3], and so on. Optomechanics, addressing the coupling of optical and mechanical degrees of freedom via radiation pressure [4], provides an ideal platform to generate and control quantum mesoscopic/macroscopic states of mechanical systems thanks to its intrinsic nonlinear light-matter interactions.Over the past few years, successful advances in nano-and micro-mechanical engineering, in particular mechanical oscillators cooled into (or close to) their ground state [5,6], have made it possible to prepare mechanical quantum states. Preparing quantum states either for the light mode or the mechanical oscillator is a fascinating (though challenging) goal in the field of optomechanics [7,8]. Nonclassical mechanical states can be generated by the optomechanical nonlinearity intrinsic in the strong coupling regime [9,10], by injecting squeezed light into the cavity (the squeezing is thus transferred from light to the mechanical degree of freedom) [11,12], by post-selected measurements on the optical field [13,14], and so on.Recently, it has been reported that hybrid atom-assisted optomechanics shows advantages in many aspects [15]. To name but a few, atoms induce an additional nonlinear effect, which enhances the optomechanical interaction and...

show abstract

“…2) and consider high-frequency mechanical oscillators (∼ 1GHz, in line with proposals for the preparation of single-phonon states reported in Ref. [18], and compatible with photonic crystal nanobeam resonators [27]), operating at 1mK (a temperature that, albeit beyond those achievable by means of standard dilution refrigerators, can be reached by employing nuclear demagnetization refrigerators [28,29]). We work in the blue detuned regime ∆ 0 < 0.…”

Section: Resultsmentioning

confidence: 86%

Engineering single-phonon number states of a mechanical oscillator via photon subtraction

et al. 2016

View full text Add to dashboard Cite

We introduce an optomechanical scheme for the probabilistic preparation of single-phonon Fock states of mechanical modes based on photo-subtraction. The quality of the produced mechanical state is confirmed by a number of indicators, including phonon statistics and conditional fidelity. We assess the detrimental effect of parameters such as the temperature of the mechanical system and address the feasibility of the scheme with state-of-the-art technology.Recent developments in quantum optomechanics [1] have shown the promises for quantum state engineering held by various experimental platforms. Squeezing of the quantum noise of a micromechanical resonator has been recently demonstrated in at least two experimental settings [2,3], while the first steps towards optomechanical entanglement have been reported in some noticeable experiments [4,5].Although the investigations performed so far have focused on Gaussian operations [6] and states, including the engineering of universal resources for quantum computation [7], similar attention has been paid to the preparation of non Gaussian states [8][9][10][11][12][13][14][15][16][17]. In this respect, the preparation of phononic number states is a particularly important goal in light of the possibility to use optomechanical devices as memories and on-demand singlephoton sources [18]. Such states have been realized experimentally by coupling the mechanical mode to a superconducting qubit [19].In this paper, we propose a novel scheme for the preparation of single-phonon number states (SPNS) that combines the features offered by the linearized optomechanical interaction and the potential for effective nonlinear effects made available by photon subtraction. In Ref. [11], one of us has demonstrated the effectiveness of photon subtraction for the preparation of non-classical states of mechanical modes: The non-classical correlations established between mechanical and optical oscillators in an optomechanical cavity, complemented by the subtraction of a single photon from the optical field, are sufficient to prepare the mechanical mode in a highly non-classical (non-Gaussian) state. Here, we extend such scheme showing the possibility to engineer a state that is very close to an ideal SPNS in both a dynamical way and at the steady-state of the optomechanical evolution. We characterize the quality of the resource thus achieved * Electronic Address: mmiskeenk16@hotmail.com † Electronic Address: mjakram@qau.edu.pk ‡ Electronic Address: m.paternostro@qub.ac.uk § Electronic Address: farhan.saif@qau.edu.pk using both state fidelity and the phonon-number statistics. The remainder of this paper is organized as follows: In Sec. I, we introduce the system under scrutiny and its equations of motion. In Sec. II, we provide the analytical form of the conditional mechanical state achieved after a single-photon subtraction on the optical field. Sec. III is devoted to the characterisation of such conditional state. Sec. IV addresses the steady-state version of the scheme put forward here, while S...

show abstract

The Vienna Nuclear Demagnetization Refrigerator

Cited by 5 publications

References 6 publications

Superconductivity in an extreme strange metal

Superconductivity in an extreme strange metal

More nonlocality with less entanglement in a tripartite atom‐optomechanical system

Engineering single-phonon number states of a mechanical oscillator via photon subtraction

Contact Info

Product

Resources

About