QCage

Versatile Qubit Sample Holder

QCage.24 is a versatile qubit sample holder featuring a low-loss printed circuit board (PCB) with 24 embedded coplanar transmission lines. The product enables high-fidelity qubit measurements at frequencies up to 18 GHz, ideal for 5–10 qubit measurements.

To minimize losses and enhance circuit coherence, the sample chip is fully suspended in QCage’s cavity. Both the cavity and PCB are optimized for resonance-free transmission. The sample holder features an EMC tight superconducting shielding enclosure to isolate samples from external electromagnetic fields. Additionally, a flux biasing magnet is mounted inside the superconducting shielding with filtered feedthroughs.

The product was previously featured in our research paper demonstrating a characterization method for qubit microwave packaging.

Efficient Magnetic Shielding

QCage Magnetic Shielding is available to protect the product from external interference and ensure proper thermalization. The magnetic shielding is achieved through a combination of an outer mu-metal shield and a superconducting aluminum can, with the shielding thermalized by a complete inner copper sleeve. This provides full Meissner effect shielding, effectively eliminating external stray magnetic fields and radiation.

Tested and Pre-installed

The product is available for LD and XLDsl systems, arriving tested and pre-installed in systems. The sample holder is installed at the mixing chamber flange, and signal transmission wiring is fully tested. Verification testing is done both during the factory installation and on-site delivery.