Flux bias lines
Control your Qubits!
Flux lines for superconducting qubits provide signals to tune qubits or tunable couplers. The key requirements to these lines are, short risetimes as well as low (contact) resistance to reduce both active and passive heating.
- Only available NbTi flex in the world
- Low pass filter at 1 GHz
- Integrated IR (infrared) filter
- Inline attenuation of 20 dB
- Contact resistance of 10 mΩ
General Specifications
| Storage temperature | 0 K to 320 K |
| Operating temperature | 0 K to 400 K (gradient) |
| Applications | Qubit flux for superconducting qubits or similar |
| Number of channels | 8 |
| Transmission type | Stripline |
| Connector type | SMA female / SMP |
| Primary flex materials | Polyimide, NbTi |
| Minimum bending radius | 5 mm |
| Required length for 180° longitudinal rotation | 10 mm |
| Vacuum feedthrough connection | KF25/40, ISO 100 side and top loader ports |
| Vacuum feedthrough leak rate | < 10-9 mbar L/s |
Cable overview
Used to
- Tune the energy gap between computational states
- Tunable couplers
- Apply general Baseband pulses or signals
Optimised for
- Low frequency bias signals
- Minimising active & passive thermal load
- Lossless DC bias current
- Ultra low noise
Key Features
- 8 Channels per flex
- 1 GHz low-pass filter
- 20 dB distributed attenuation
- NbTi Superconducting lines
The product is provided with coaxial SMA/SMP connector blocks to interface to the room-temperature electronics and the chipholder at the mK stage. Vacuum feedthroughs are designed to carry multiple flexes and are compatible with most fridge types. The chain of integrated attenuators and low pass filters is configured for flux bias currents, shielding the bias loop from undesired high frequency noise while allowing short risetimes. Below the 100 mK plate, integrated infrared filtering is positioned and thermalized with a slope of -1.5 dB/GHz to further filter out high frequency radiation.
The passive heatload is 600 pW per channel at 10 mK due to the superconducting material used. Microwave performance of the flux lines is shown in the figure below.
Microwave Response
A flux line I/O chain allows base-band (0-2 GHz) access to your circuit, typically terminated by an inductive component on your chip like a flux loop. With a DC bias current one tunes the frequency of the qubit or the magnitude of the coupler. In time domain one can tune this in nanosecond timescale.
The Cri/oFlex® flux line is configured completely for this task. With a low pass filter at 1 GHz, a 20 dB attenuator, and a strong IR-filter, this setup allows you to control your qubit without opening unwanted noise channels.
Cross talk
Cross talk is what we experience daily. Whether it is picking up unwanted conversations in the train, or a phone connection suffering from interference.
Cri/oFlex® has been designed such that each qubit is addressed individually. Learn more about cross talk in our core technology section.
How to
Integrate
Cri/oFlex® into your system?
Cri/oFlex® can fit in your system in many ways and Delft Circuits has multiple approaches to find a perfect fit for your wishes, options range from a one-stop-shop in cabling solutions or a full service I/O provider designing a specific solution for your I/O challanges.
Need some help picking the right option?
First questions to ask yourself is how your system is currently wired. Do you have a port available or full loader you would like to install, upgrade or add wiring to?
For ports Delft Circuits recommends choosing from our wiring ports solution, if you want to fill a single port with more cables or get a lower heatload etc. etc. and already know exactly what cables you want pick the Wiring ports option. if you want a hassle free solution with installation, service, calibration. We recommend going for the turn-key solution and see what else we can do for you.
Delft Circuits recommends
Wiring ports
Delft Circuits recommends
Turn-key
For ports Delft Circuits recommends choosing from our wiring ports solution, if you want to fill a loader with more cables or get a lower heatload etc.. If you want a hassle free solution with installation etc. etc. we recommend going for the turn-key solution and see what else we can do for you
Delft Circuits recommends
Delft Circuits recommends
If you are building a new system we recommend looking at everything we have to offer for you, next to just I/O we can help you design, help you optimize, do cryogenic calculations, calibrations and much more.
Delft Circuits recommends
Wiring ports
Have a spare port in your fridge and want to add extra lines or replace an existing wiring port with a higher density cabling solution?
We supply vacuum feedthroughs, Thermal clamps, Brackets and Cri/oFlex® laminates for all standard ports you will find in dilution refridgerators.
- Fits for all standard ports
- Out of the box solution
- Upgrade existing systems
Loaders
Delft Circuits can supply fully pre-assembled loaders with Cri/oFlex® cabling inside.
We supply top- and sideloaders for all common brands such as Bluefors, Oxford and Leiden Cryogenics.
The advantages of pre-assambled loaders:
- More channels in a loader
- Plug and play cabling solution
- Engineered for your application
Turn-key
Trying to lead the way in the quantum revolution? We can match your pace in cabling solutions.
Outfitting full systems with cutting edge I/O solutions. Massively scaling cabling solutions for everyone that needs the edge in the quantum race.
Our options:
- Full-service provider
- Full fletched solutions
- Innovative design
Dive deeper into
Cri/oFlex® technology
Learn all about what makes our technology specially fitted for the quantum industry.
