// On the cloud

Meet Boson 4

// World Record

Record-Breaking Bit-Flip Lifetime

Cat qubits have a wonderful property: they can exponentially suppress bit-flip errors while only linearly increasing phase-flip errors. With bit-flip lifetime surpassing 7 minutes, Boson 4 beats any other superconducting qubit.

Cat qubits record 430s bit-flip plot alice & bob


One Dimension of Error Correction


When the bit-flip lifetime of a qubit is long enough, bit-flips happen so rarely there is no need to correct them.

This reduces the number of qubits required to build a fault-tolerant quantum computer by up to 200 times.

This is why we’re so excited about Boson 4: it is the experimental proof of a key element in our roadmap to a fault-tolerant quantum computer.



Boson 1

Boson 1 showed that bit-flips could be suppressed exponentially while only linearly increasing phase-flips.

However, bit-flip lifetime saturated at 1 ms because of the presence of a transmon used to measure the qubit's state.



Boson 2

Boson 2 demonstrated that by removing the transmon, bit-flip lifetime could reach 100 seconds.

However, without a transmon, this chip lacked the possibility to measure phase-flip and we couldn't prove it was quantum.



Boson 3

Boson 3 reaches a bit-flip time of over 10 seconds using a new design, TomCat.

With a reliable measure of both bit-flip and phase-flip, and no transmon, Boson 3 gets featured in the scientific journal Nature.



Boson 4

Boson 4 builds upon the measurement protocols developed with Boson 3 while further improving bit-flip lifetime to more than 7 minutes. [Preprint coming soon]

Boson 4 is the first cat qubit available for anyone to test over the cloud.

// The road covered

One Big Step Towards our Target

We believe that a useful quantum computer should feature at least 100 logical qubits and a 10e-8 error rate. Boson 4 addresses and solves the first challenge to meet this target, bit-flip time.

Cat Qubits Boson 4 vs LDPC Target Alice & Bob

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    Join us in the lab and reproduce these findings yourself through Google Cloud

// Next steps

Our Path to Fault Tolerance

Boson series processors are single-qubit chips and an essential first step on the way to a fault-tolerant quantum computer. Alice & Bob is already working on two multi-qubit chip generations: Hydrogen, to detect quantum errors, and Helium, to exponentially remove phase-flips through error correction.


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