Measurement of the effective dissipation in an rf SQUID system

Ruggiero, B.; Corato, V.; Granata, C.; Longobardi, L.; Rombetto, S.; Silvestrini, P.

doi:10.1103/physrevb.67.132504

Cited by 17 publications

(9 citation statements)

References 23 publications

(21 reference statements)

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“…It could be noted that GO, depending on its fabrication conditions, could be semiconductor or conductor with an electrical conductivity ranging between 1 S/cm down to 1 × 10 –4 S/cm. For this reason, a preliminary study of the GO thin film has been carried out, using a very low noise facility 47 , 48 . The GO-based samples used for the electrical investigation are represented by two narrow lines made of GO and rGO, respectively, with a length of 10 mm, a width of 1 mm and a thickness of 0.1 mm.…”

Section: Resultsmentioning

confidence: 99%

Reduced graphene oxide on silicon-based structure as novel broadband photodetector

Bonavolontà

Vettoliere

Falco

et al. 2021

Sci Rep

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Heterojunction photodetector based on reduced graphene oxide (rGO) has been realized using a spin coating technique. The electrical and optical characterization of bare GO and thermally reduced GO thin films deposited on glass substrate has been carried out. Ultraviolet–visible–infrared transmittance measurements of the GO and rGO thin films revealed broad absorption range, while the absorbance analysis evaluates rGO band gap of about 2.8 eV. The effect of GO reduction process on the photoresponse capability is reported. The current–voltage characteristics and the responsivity of rGO/n-Si based device have been investigated using laser diode wavelengths from UV up to IR spectral range. An energy band diagram of the heterojunction has been proposed to explain the current versus voltage characteristics. The device demonstrates a photoresponse at a broad spectral range with a maximum responsivity and detectivity of 0.20 A/W and 7 × 1010 cmHz/W, respectively. Notably, the obtained results indicate that the rGO based device can be useful for broadband radiation detection compatible with silicon device technology.

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Section: Resultsmentioning

confidence: 99%

Reduced graphene oxide on silicon-based structure as novel broadband photodetector

Bonavolontà

Vettoliere

Falco

et al. 2021

Sci Rep

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“…The magnetization reversal is defined by the minimal field value at which the energy barrier between the metastable minimum and the stable one vanishes. This process is analogue to the supercurrent decay in a Josephson junction or the decay from the metastable flux statesin a rf SQUID; also in these cases, there is multi or double well potential and the escape process occurs when the bias current or the bias magnetic flux reaches the critical values [228,247,248]. Therefore, the magnetization reversal in a nanoparticle is a stochastic process characterized by thermal and quantum fluctuations.…”

Section: Nanomagnetism Applicationsmentioning

confidence: 99%

Nano Superconducting Quantum Interference device: A powerful tool for nanoscale investigations

2016

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The magnetic sensing at nanoscale level is a promising and interesting research topic of nanoscience. Indeed, magnetic imaging is a powerful tool for probing biological, chemical and physical systems. The study of small spin cluster, like magnetic molecules and nanoparticles, single electron, cold atom clouds, is one of the most stimulating challenges of applied and basic research of the next years. In particular, the magnetic nanoparticle investigation plays a fundamental role for the modern material science and its relative technological applications like ferrofluids, magnetic refrigeration and biomedical applications, including drug delivery, hyper-thermia cancer treatment and magnetic resonance imaging contrast-agent. Actually, one of the most ambitious goals of the high sensitivity magnetometry is the detection of elementary magnetic moment or spin. In this framework, several efforts have been devoted to the development of a high sensitivity magnetic nanosensor pushing sensing capability to the individual spin level. Among the different magnetic sensors, Superconducting QUantum Interference Devices (SQUIDs) exhibit an ultra high sensitivity and are widely employed in numerous applications. Basically, a SQUID consists of a superconducting ring (sensitive area) interrupted by two Josephson junctions. In the recent years, it has been proved that the magnetic response of nano-objects can be effectively measured by using a SQUID with a very small sensitive area (nanoSQUID). In fact, the sensor noise, expressed in terms of the elementary magnetic moment (spin or Bohr magneton), is linearly dependent on the SQUID loop side length. For this reason, SQUIDs have been progressively miniaturized in order to improve the sensitivity up to few spin per unit of bandwidth. With respect to other techniques, nanoSQUIDs offer the advantage of direct measurement of magnetization changes in small spin systems. In this

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“…This is encouraging if the D = T /Re 2 estimate is correct, where we needed 1MΩ at T=40mK. The exponential fit shows that the effective resistance R is determined by tunneling of [24]. Q increases exponentially with decreasing temperature, following the exponential law Q = Q0e B/T , with Q0 = 35.37 and B=15.45K.…”

Section: Implementation a Dissipationmentioning

confidence: 99%

“…It is evident, as exemplified by the latter formula, that a necessary and-less evident-perhaps also a sufficient condition for quantum behavior of the system is a low classical dissipation. In the present context this implies a large value of R. Therefore we present some experimental data on this point, collected in the thermal regime for superconducting devices based on SQUIDs [24].…”

Section: Implementation a Dissipationmentioning

confidence: 99%

Adiabatic evolution of a coupled-qubit Hamiltonian

et al. 2003

Self Cite

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We present a general method for studying coupled qubits driven by adiabatically changing external parameters. Extended calculations are provided for a two-bit Hamiltonian whose eigenstates can be used as logical states for a quantum CNOT gate. From a numerical analysis of the stationary Schroedinger equation we find a set of parameters suitable for representing CNOT, while from a time-dependent study the conditions for adiabatic evolution are determined. Specializing to a concrete physical system involving SQUIDs, we determine reasonable parameters for experimental purposes. The dissipation for SQUIDs is discussed by fitting experimental data. The low dissipation obtained supports the idea that adiabatic operations could be performed on a time scale shorter than the decoherence time.

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Measurement of the effective dissipation in an rf SQUID system

Cited by 17 publications

References 23 publications

Reduced graphene oxide on silicon-based structure as novel broadband photodetector

Reduced graphene oxide on silicon-based structure as novel broadband photodetector

Nano Superconducting Quantum Interference device: A powerful tool for nanoscale investigations

Adiabatic evolution of a coupled-qubit Hamiltonian

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