CORDIS - EU research results

SUPERinductance for hardware-PROTECTED superconducting qubits

Project description

Quantum computing gets a boost from a streamlined quantum error correction approach

Quantum coherence, or the superposition of quantum mechanical states typically lasting only a fraction of a second, enables the formation of two quantum waves that coherently interfere with each other. It is the basis of quantum computing, so scientists have developed quantum error correction techniques to protect quantum information from errors due to decoherence. Current solutions are highly resource-intensive and will create roadblocks to upscaling for next-generation applications and widespread use. The EU-funded SuperProtected project will develop a solution that could increase coherence time by a factor of 100 while significantly simplifying hardware requirements.


The quantum computer dream is driven by promises of unprecedented capabilities but is also facing a stark reality: quantum coherence is as powerful as it is difficult to protect. Quantum Error Correction (QEC) aims to extend coherence using redundancies but leads to solutions that are extremely resource-intensive: at present, protecting one bit of information requires at least ten thousand physical qubits. The main objective of this proposal is to engineer a new type of superconducting qubit, which will be intrinsically protected against de-coherence. Instead of matching the qubit states to the number of Cooper pairs or flux quanta of a given circuit, as is usually done, SuperProtected will exploit a completely new encoding scheme: quantum information will be stored as the parity of the number of Cooper pairs. This will be achieved by building a circuit component where charge transport occurs as pairs of Cooper pairs (4e-tunneling) while the standard single pair transport (2e-tunneling), or Josephson current, is reduced to zero. This new paradigm implies inductances with unprecedented value (10μH), also known as superinductances. The novel approach builds on two technological steps: a new high-kinetic inductance superconductor (InOx) and suspended silicon membranes. Improvement of the coherence time over current state-of-the-art is expected to be two orders of magnitude. The proposed qubits offer another major advantage: protected gates can be implemented using a simple modification of the architecture. The resulting protected qubit will extend the frontiers of the current knowledge in QEC and bring down the hardware requirements for a logical qubit by several orders of magnitude. Such a result would considerably change the quantum computing landscape.

Host institution

Net EU contribution
€ 2 132 595,00
75794 Paris

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Ile-de-France Ile-de-France Paris
Activity type
Research Organisations
Total cost
€ 2 132 595,00

Beneficiaries (1)