Ultra-low-loss
IR-blocking filters

Infrared radiation shortens qubit coherence. HERD drains it; your signal passes untouched.

Insertion loss
< 0.15 dB
Attenuation
> 60 dB above 70 GHz
Request quoteHERD-2 datasheet

Measured in systems at Yale · Princeton · PTB · EPFL · Chalmers

Why HERD

One filter for readout, charge, and flux lines alike.

On readout lines

<0.15 dB in-band: industry leading in-band performance, providing minimum loss between the QPU and the first amplifier.

On charge lines

Flat response with <0.1 dB ripple: preserves your pulse shapes and leaves the attenuation profile to your attenuators.

On flux lines

mA bias with low dissipation: allows for high bias currents while saving cooling power.

On every line

>60 dB stopband from 70 to 145 GHz and beyond: Cooper-pair-breaking radiation is drained before it reaches the QPU.

The measured outcome

Published setups using HERD reach sub-Hz quasiparticle tunneling rates, and provide coherence improvements in state-of-the-art QPUs.

Fully non-magnetic

Non-magnetic, cryo-compatible material choices: no added flux noise next to superconducting or spin qubits.

How the filter does this → Technology

How HERD stacks up

Room-temperature measurements up to 140 GHz.

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Validation from the field

Preprints and peer-reviewed publications from laboratories running HERD filters in operating quantum systems.

2025·Yale University·Quasiparticle bursts

Recovery dynamics of a gap-engineered transmon after a quasiparticle burst

Gap-engineered transmons show reduced sensitivity to quasiparticle bursts. Burst rates drop by a factor of a few, but elevated substrate temperature during radiation impacts lets quasiparticles overcome the engineered gap. Relaxation recovers in ~0.7 ms, while chip heating persists for several milliseconds, revealing limits of gap engineering without improved phonon evacuation.

doi.org/10.48550/arXiv.2505.08104
All publications citing HERD

The HERD products

Two generations of ultra-low-loss IR-blocking filters for superconducting and spin qubits.

HERD-2 current-generation IR-blocking filter

2nd generation · current

HERD-2

Non-magnetic inline filter with ultra-low in-band loss and deep high-frequency attenuation, validated to 145 GHz. Reduces quasiparticle generation at the cold stage.

Insertion loss
<0.15 dB
Stopband
>60 dB above 70 GHz
Validated
to 145 GHz
Connectors
SMA / SMP / SMPM / SMPS
View HERD-2

How can we help?

Quotes, integration questions, or custom connector configurations. Reach the team directly.

Sales inquiriessales@swedenquantum.com
General inquiriesinfo@swedenquantum.com