[LnLn0Ln] lanthanide complex as a qubit with embedded quantum error correction†

We show that a [Er–Ce–Er] molecular trinuclear coordination compound is a promising platform to implement the three-qubit quantum error correction code protecting against pure dephasing, the most important error in magnetic molecules. We characterize the compound by performing thorough magnetometry, specifi cheat and electron paramagnetic resonance measurements on [Er–Ce–Er] and on the [Lu–Ce–Lu] and [Er–La–Er] analogues. We then demonstrate by numerical simulations that each [Er–Ce–Er] complex can effi ciently encode a logical qubit protected from pure dephasing.