By studying the losses as a function of temperature and microwave power, we quantitatively extract different components of loss, such as radiation into uncontrolled electromagnetic modes and resistive losses arising from broken Cooper pairs. In this work, we perform systematic measurements of over 100 microwave resonators made from tantalum patterned on sapphire. Here, we identify key sources of loss and noise in this new material system. Recent work has shown a marked improvement in qubit lifetime and coherence by employing tantalum as the superconducting metal in the capacitor of a superconducting qubit. Building large-scale systems that are robust to computational errors will require improvements in the underlying hardware to extend the quantum coherence of individual qubits. Superconducting qubits are one of the most successful quantum platforms, and they have been integrated into some of the largest processors to date. In these devices, the surface and bulk TLS contributions to loss are comparable, showing that systematic improvements in materials on both fronts are necessary to improve qubit coherence further. In this regime, we measure resonators with internal quality factors ranging from 5 to 15 × 10 6, comparable to the best qubits reported. Finally, we quantify the impact of the chemical processing at single-photon powers, the relevant conditions for qubit device performance. ![]() With four different surface conditions, we quantitatively extract the linear absorption associated with different surface TLS sources. Moreover, we show that surface TLSs can be altered with chemical processing. By studying the dependence of loss on temperature, microwave photon number, and device geometry, we quantify materials-related losses and observe that the losses are dominated by several types of saturable two-level systems (TLSs), with evidence that both surface and bulk related TLSs contribute to loss. Here, we perform systematic, detailed measurements of superconducting tantalum resonators in order to disentangle sources of loss that limit state-of-the-art tantalum devices. Recently discovered tantalum-based qubits exhibit record lifetimes exceeding 0.3 ms. As the RF Isolator will add some amount of insertion loss and product reflections of its own (non-ideal VSWR), this must also be taken into consideration when selecting an isolator.Superconducting qubits are a leading system for realizing large-scale quantum processors, but overall gate fidelities suffer from coherence times limited by microwave dielectric loss. It is important to select an RF Isolator that matches the signal chain requirements, such as frequency range and power. RF Isolators can be used to protect any component or section of a signal chain from reverse reflections, but are most often used to protect active devices, such as transceivers, power amplifiers (PAs), low-noise amplifiers (LNAs), and mixers. Reverse power continuous-wave and/or peak (dB).Forward power handling continuous-wave and/or peak (dB). ![]() The isolation of an RF Isolator is directly related to the quality of the match of the termination. ![]() It is also likely that pre-manufactured RF Isolators will be more compact and plug-and-play compared to a RF Isolator made from an off-the-shelf RF Circulator. However, factory designed RF Isolators will likely have much better matched terminations and are designed and tested to operate over the entire frequency range and to the specified power levels. It is possible to make an RF Isolator from an RF Circulator by just terminating the reverse port. With a well matched termination on the reverse port, the majority of the reflected/reverse signal energy from the output port will be directed to the termination and dissipated and heat. It is critical for an RF Isolator to have a well matched termination in the reverse port to optimize the isolation. RF Circulators/RF Isolators are typically passive ferrite devices that are made in such a way that the internal magnetic fields within the component steer the electromagnetic waves incident at the ports in a certain direction, with these waves exciting at the nearest port in the direction of travel.Īs the name implies, RF Isolators are predominately used to isolate upstream signal chain components, which are typically more sensitive components, from reflections from downstream components. This modification of RF Isolators only allows for signal energy to pass in the forward direction, in reference to the signal chain, and heavily “isolates” the upstream signal chain from any reverse reflections or noise/interference injection. RF Isolators are specific cases of RF Circulators where one of the three ports, typically the reverse port in reference to the signal chain, is terminated.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |