Highly Sensitive Superconducting Quantum-Interference Proximity Transistor

Ronzani, Alberto; Altimiras, C.; Giazotto, Francesco

doi:10.1103/physrevapplied.2.024005

Cited by 47 publications

(90 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This effect allows us to perform magnetometric measurement. In twoterminal SQUIPTs, high sensitivities have been demonstrated [1,5]. In the following, we evaluate the sensitivity of the ω-SQUIPT.…”

Section: Magnetometric Characteristics Of the ω-Squiptmentioning

confidence: 99%

“…For an Al-Cu-based device, these parameters correspond to L i ≈ 90 nm and L i ≈ 30 nm, respectively, and a contact length in each arm l i ≈ 20 nm. All these values are achievable with state-of-the-art nanofabrication techniques [5,37]. Considering an electrical setup where the ω-SQUIPT is biased with a proper current I b , the voltage drop depends on flux, giving the flux to voltage characteristics V ( ) (see Fig.…”

Section: Magnetometric Characteristics Of the ω-Squiptmentioning

confidence: 99%

“…The phase-controlled density of states (DOS) of the proximized nanowire makes the SQUIPT an ideal building block for the realization of heat nanovalves [4] or very sensitive and ultra-low-power dissipation magnetometers [5][6][7][8] able to succeed the state-of-the-art SQUID technologies, with particular interest in single-spin detection [9].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Coherent transport properties of a three-terminal hybrid superconducting interferometer

et al. 2017

View full text Add to dashboard Cite

Coherent transport properties of a three-terminal hybrid superconducting interferometerVischi, F.; Carrega, M.; Strambini, E.; D'Ambrosio, S.; Bergeret, F. S.; Nazarov, Yuli; Giazotto, F. Important noteTo cite this publication, please use the final published version (if applicable). Please check the document version above. CopyrightOther than for strictly personal use, it is not permitted to download, forward or distribute the text or part of it, without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license such as Creative Commons. Takedown policyPlease contact us and provide details if you believe this document breaches copyrights. We will remove access to the work immediately and investigate your claim. We present an exhaustive theoretical analysis of a double-loop Josephson proximity interferometer, such as the one recently realized by Strambini et al. for control of the Andreev spectrum via an external magnetic field. This system, called ω-SQUIPT, consists of a T-shaped diffusive normal metal (N ) attached to three superconductors (S) forming a double-loop configuration. By using the quasiclassical Green-function formalism, we calculate the local normalized density of states, the Josephson currents through the device, and the dependence of the former on the length of the junction arms, the applied magnetic field, and the S/N interface transparencies. We show that by tuning the fluxes through the double loop, the system undergoes transitions from a gapped to a gapless state. We also evaluate the Josephson currents flowing in the different arms as a function of magnetic fluxes, and we explore the quasiparticle transport by considering a metallic probe tunnel-coupled to the Josephson junction and calculating its I -V characteristics. Finally, we study the performances of the ω-SQUIPT and its potential applications by investigating its electrical and magnetometric properties.

show abstract

Section: Magnetometric Characteristics Of the ω-Squiptmentioning

confidence: 99%

Section: Magnetometric Characteristics Of the ω-Squiptmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Coherent transport properties of a three-terminal hybrid superconducting interferometer

et al. 2017

View full text Add to dashboard Cite

show abstract

“…It would not be possible to make justice to the vast literature on the subject; some examples are Refs. [6][7][8][9][10][11][12][13][14][15][16][17][18].…”

Section: Introductionmentioning

confidence: 99%

The Stationary SQUID

Berger

2018

J Low Temp Phys

View full text Add to dashboard Cite

In the customary mode of operation of a SQUID, the electromagnetic field in the SQUID is an oscillatory function of time. In this situation, electromagnetic radiation is emitted, and couples to the sample. This is a back-action that can alter the state that we intend to measure. A circuit that could perform as a stationary SQUID consists of a loop of superconducting material that encloses the magnetic flux, connected to a superconducting and to a normal electrode. This circuit does not contain Josephson junctions, or any other miniature feature. We study the evolution of the order parameter and of the electrochemical potential in this circuit; they converge to a stationary regime and the voltage between the electrodes depends on the enclosed flux. We obtain expressions for the power dissipation and for the heat transported by the electric current; the validity of these expressions does not rely on a particular evolution model for the order parameter. We evaluate the influence of fluctuations. For a SQUID perimeter of the order of 1µm and temperature 0.9T c , we obtain a flux resolution of the order of 10 −5 Φ 0 /Hz 1/2 ; the resolution is expected to improve as the temperature is lowered.

show abstract

“…Therefore, the probability for electrons to tunnel between N and S R depends on the sign of the spin. The device resembles the superconducting quantum interference proximity transistor (SQUIPT) [8][9][10][11][12] which has been well-studied in several experiments; the crucial structural difference in our device is that the thermoelectric transistor lies in the presence of the FI layer.…”

mentioning

confidence: 99%

Proposal for a phase-coherent thermoelectric transistor

Giazotto

Robinson

Moodera

et al. 2014

Applied Physics Letters

View full text Add to dashboard Cite

Identifying materials and devices which offer efficient thermoelectric effects at low temperature is a major obstacle for the development of thermal management strategies for low-temperature electronic systems. Superconductors cannot offer a solution since their near perfect electron-hole symmetry leads to a negligible thermoelectric response; however, here we demonstrate theoretically a superconducting thermoelectric transistor which offers unparalleled figures of merit of up to ∼ 45 and Seebeck coefficients as large as a few mV/K at sub-Kelvin temperatures. The device is also phasetunable meaning its thermoelectric response for power generation can be precisely controlled with a small magnetic field. Our concept is based on a superconductor-normal metal-superconductor interferometer in which the normal metal weak-link is tunnel coupled to a ferromagnetic insulator and a Zeeman split superconductor . Upon application of an external magnetic flux, the interferometer enables phase-coherent manipulation of thermoelectric properties whilst offering efficiencies which approach the Carnot limit.It is known that electron-hole symmetry breaking is essential for a material to posses a finite thermoelectric figure of merit 1,2 . In principle, conventional superconductors have a near perfect symmetric spectrum and therefore are not suitable for thermoelectric devices. However, if the density of states is spin-split by a Zeeman field a superconductor-ferromagnet hybrid device can provide a thermoelectric effect 3-5 with a figure of merit close to 1. Here we propose a multifunctional phase-coherent superconducting transistor in which the thermoelectric efficiency is tunable through an externally applied magnetic flux. A giant Seebeck coefficient of several mV/K and a figure of merit close to ∼ 45 is predicted for realistic materials parameters and materials combinations.The phase-coherent thermoelectric transistor is based on two building blocks. The first one is sketched in Fig. 1(a) and consists of a superconducting film (S R ) tunnel-coupled to a normal metal (N) by a ferromagnetic insulator (FI). The latter induces an exchange field (h) in S R which leads to a Zeeman spin-split superconducting DoS. The spectrum for spin-up (↑) and spin-down (↓) electrons is given bywhere| is the conventional Bardeen-Cooper-Schrieffer DoS in a superconductor, E is the energy, ∆ R is the order parameter, and Γ accounts for broadening. Due to the presence of the spin-splitting field, ∆ R depends on temperature (T ) and h. While the total DoS of S R , ν S R (E) = ν S R↑ (E) + ν S R↓ (E), is electron-hole symmetric [ Fig. 1(b)], the spin-dependent a) Electronic mail: giazotto@sns.it b) Electronic mail: jjr33@cam.ac.uk c) Electronic mail: sebastian bergeret@ehu.es ν S R↑(↓) (E) components are no longer even functions of the energy. This means that electron-hole imbalance can, in principle, be achieved using a spin-filter contact with a normal metal. This would yield a finite thermoelectric effect 3,4 in the N/FI/S R heterostructure shown in F...

show abstract

Highly Sensitive Superconducting Quantum-Interference Proximity Transistor

Cited by 47 publications

References 33 publications

Coherent transport properties of a three-terminal hybrid superconducting interferometer

Coherent transport properties of a three-terminal hybrid superconducting interferometer

The Stationary SQUID

Proposal for a phase-coherent thermoelectric transistor

Contact Info

Product

Resources

About