Phase sensitive amplification in a superconducting stripline resonator integrated with a dc-SQUID (original) (raw)
Related papers
EPL (Europhysics Letters), 2009
We utilize a superconducting stripline resonator containing a dc-SQUID as a strong intermodulation amplifier exhibiting a signal gain of 25 dB and a phase modulation of 30 dB. Studying the system response in the time domain near the intermodulation amplification threshold reveals a unique noise-induced spikes behavior. We account for this response qualitatively via solving numerically the equations of motion for the integrated system. Furthermore, employing this device as a parametric amplifier yields a gain of 38 dB in the generated side-band signal.
Self-oscillations in a superconducting stripline resonator integrated with a DC-SQUID
Eprint Arxiv 0907 3267, 2009
We study self-sustained oscillations (SO) in a Nb superconducting stripline resonators (SSR) integrated with a DC superconducting quantum interface devices (SQUID). We find that both the power threshold where these oscillations start and the oscillations frequency are periodic in the applied magnetic flux threading the SQUID loop. A theoretical model which attributes the SO to a thermal instability in the DC-SQUID yields a good agreement with the experimental results. This flux dependant nonlinearity may be used for quantum state reading of a qubit-SSR integrated device.
Applied Physics Letters, 2009
We study self-sustained oscillations in a Nb superconducting stripline resonator integrated with a dc superconducting quantum interference device ͑SQUID͒. We find that both the power threshold where these oscillations start and the oscillation frequency are periodic in the applied magnetic flux threading the SQUID loop. A theoretical model which attributes the self-sustained oscillations to a thermal instability in the dc-SQUID yields a good agreement with the experimental results. This flux dependant nonlinearity may be used for quantum state reading of a qubit-superconducting resonator integrated device.
Intermode Dephasing in a Superconducting Stripline Resonator (Supplementary Material)
Physical Review B
We study a superconducting stripline resonator ͑SSR͒ made of niobium, which is integrated with a superconducting interference device ͑SQUID͒. The large nonlinear inductance of the SQUID gives rise to a strong Kerr nonlinearity in the response of the SSR, which in turn results in strong coupling between different modes of the SSR. We experimentally demonstrate that such intermode coupling gives rise to dephasing of microwave photons. The dephasing rate depends periodically on the external magnetic flux applied to the SQUID, where the largest rate is obtained at half integer values ͑in units of the flux quantum͒. To account for our result we compare our findings with theory and find good agreement.
Intermode dephasing in a superconducting stripline resonator
Physical Review B, 2010
We study a superconducting stripline resonator ͑SSR͒ made of niobium, which is integrated with a superconducting interference device ͑SQUID͒. The large nonlinear inductance of the SQUID gives rise to a strong Kerr nonlinearity in the response of the SSR, which in turn results in strong coupling between different modes of the SSR. We experimentally demonstrate that such intermode coupling gives rise to dephasing of microwave photons. The dephasing rate depends periodically on the external magnetic flux applied to the SQUID, where the largest rate is obtained at half integer values ͑in units of the flux quantum͒. To account for our result we compare our findings with theory and find good agreement.
Applied Physics Letters, 2008
Due to their superior noise performance, SQUIDs are an attractive alternative to high electron mobility transistors for constructing ultra-low-noise microwave amplifiers for cryogenic use. We describe the use of a lumped element SQUID inductively coupled to a quarter wave resonator. The resonator acts as an impedance transformer and also makes it possible for the first time to accurately measure the input impedance and intrinsic microwave characteristics of the SQUID. We present a model for input impedance and gain, compare it to the measured scattering parameters, and describe how to use the model for the systematic design of low-noise microwave amplifiers with a wide range of performance characteristics.
Physical Review B, 2011
We study the metastable response of a highly hysteretic DC-SQUID made of a Niobium loop interrupted by two nano-bridges. We excite the SQUID with an alternating current and with direct magnetic flux, and find different stability zones forming diamond-like structures in the measured voltage across the SQUID. When such a SQUID is embedded in a transmission line resonator similar diamond structures are observed in the reflection pattern of the resonator. We have calculated the DC-SQUID stability diagram in the plane of the exciting control parameters, both analytically and numerically. In addition, we have obtained numerical simulations of the SQUID equations of motion, taking into account temperature variations and non-sinusoidal current-phase relation of the nano-bridges. Good agreement is found between experimental and theoretical results.
Applied Physics Letters, 1999
A low-noise single-chip two-stage superconducting quantum interference device ͑SQUID͒ system with a double relaxation oscillation SQUID as the second stage has been realized. The system was operated in a direct voltage readout mode, with a closed loop bandwidth up to 1 MHz. Operated at 4.2 K, the white flux noise measured in flux locked loop was 1.3 ⌽ 0 /ͱHz, corresponding to an energy sensitivity of ⑀Ϸ27h. Owing to the large flux-to-voltage transfer of up to 3.6 mV/⌽ 0 , the room-temperature preamplifier noise did not dominate the overall flux noise.
A wideband, low-noise superconducting amplifier with high dynamic range
Nature Physics, 2012
Amplifiers are ubiquitous in electronics and play a fundamental role in a wide range of scientific measurements. From a user's perspective, an ideal amplifier has very low noise, operates over a broad frequency range, and has a high dynamic range-it is capable of handling strong signals with little distortion. Unfortunately, it is difficult to obtain all of these characteristics simultaneously. For example, modern transistor amplifiers offer multi-octave bandwidths and excellent dynamic range. However, their noise remains far above the fundamental limit set by the uncertainty principle of quantum mechanics.[1] Parametric amplifiers, which predate transistor amplifiers and are widely used in optics, exploit a nonlinear response to transfer power from a strong pump tone to a weak signal. If the nonlinearity is purely reactive, i.e. nondissipative, in theory the amplifier noise can reach the quantum-mechanical limit.[2] Indeed, microwave frequency superconducting Josephson parametric amplifiers[3, 4] do approach the quantum limit, but generally are narrow band and have very limited dynamic range. In this paper, we describe a superconducting parametric amplifier that overcomes these limitations. The amplifier is very simple, consisting only of a patterned metal film on a dielectric substrate, and relies on the nonlinear kinetic inductance of a superconducting transmission line. We measure gain extending over 2 GHz on either side of an 11.56 GHz pump tone, and we place an upper limit 1
A coupled DC SQUID with low 1/f noise
IEEE Transactions on Appiled Superconductivity, 1993
A low-noise coupled DC superconducting quantum interference device (SQUID) especially optimized for low frequency is discussed. Using large Josephson junctions and a low loop inductance the contribution of the critical current fluctuation to 1/f noise can be minimized. To minimize the inductance the Josephson junctions are placed in the center of the washer close to the SQUID loop. A scaled-up