Institut für Physikalische Chemie, Universität Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart, Germany.
Centre for Biomolecular Magnetic Resonance, Institute of Physical and Theoretical Chemistry, Goethe University Frankfurt, D-60438 Frankfurt am Main, Germany.
Nat Commun. 2014 Oct 20;5:5304. doi: 10.1038/ncomms6304.
The successful development of a quantum computer would change the world, and current internet encryption methods would cease to function. However, no working quantum computer that even begins to rival conventional computers has been developed yet, which is due to the lack of suitable quantum bits. A key characteristic of a quantum bit is the coherence time. Transition metal complexes are very promising quantum bits, owing to their facile surface deposition and their chemical tunability. However, reported quantum coherence times have been unimpressive. Here we report very long quantum coherence times for a transition metal complex of 68 μs at low temperature (qubit figure of merit QM=3,400) and 1 μs at room temperature, much higher than previously reported values for such systems. We show that this achievement is because of the rigidity of the lattice as well as removal of nuclear spins from the vicinity of the magnetic ion.
量子计算机的成功研制将改变世界，而目前的互联网加密方法也将失效。然而，目前还没有研制出哪怕是初步能与传统计算机相媲美的量子计算机，这是因为缺乏合适的量子位。量子位的一个关键特征是相干时间。过渡金属配合物是非常有前途的量子位，因为它们易于进行表面沉积并且具有化学可调性。但是，已报道的量子相干时间却不尽人意。在这里，我们报道了一种过渡金属配合物在低温下具有非常长的量子相干时间，为 68μs（量子比特品质因数 QM=3400），在室温下为 1μs，远高于之前报道的此类系统的值。我们表明，这一成就归因于晶格的刚性以及从磁性离子附近除去核自旋。
