The imperfections of artificial nanometer objects, such as quantum dots, supports the vision of the use of standard natural objects such as atoms and molecules

Recently, researchers from the University of Manchester (United Kingdom) [1] drew attention to the special spin molecular clusters containing a single nickel ion Ni 2 + ions and seven of chromium Cr 3 +. The main condition of such clusters with the spin S = 1 / 2 and can be used as spin qubits. Measuring time dekogerentizatsii technique using electron spin resonance (ESR) has a very long time. This in itself is, of course, delighted but it was necessary to show that during this time you can perform a large number of quantum operations, including management of the state of individual qubits, as well as the operations between two qubits.

Fig. 1. Two spin cluster related element that contains one copper ion Cu 2 + (a) and two copper ions (b)

Management of qubits can be implemented with the help of ESR, ie, sending to the system defined by electromagnetic pulses. We show that this procedure can be repeated over time dekogerentizatsii. Then there is the problem of addressing the individual qubits. The authors suggest plant molecules on a substrate and then, perhaps, control electrodes. However, in molecular electronics problem electrodes such small size has not yet been resolved. Very often a means of addressing the individual spin qubits is called a spatial gradient of magnetic field, which specifies each qubits their frequency EPR. However, the desired gradient is not yet possible to create.

To perform operations with two qubits need to interact between them. Suggested as a link between the individual clusters using special molecules that contain one or two copper ions Cu 2 + (Fig. 1). A copper ion is itself a spin qubits (Fig. 1a). By changing its status, you can manage the interaction between the clusters. If the two copper ions, the possibility of significantly increasing. The main condition of the binding molecule singlet, the total spin is zero. The interaction between the clusters and the disabled. If you bring a molecule by using an electromagnetic pulse excited in the ferromagnetic state with spin S = 1 / 2, in this case included the interaction between the clusters. This, of course, distant perspective. And yet experimentally determined strength of the interaction between the clusters for different condition of the binding molecule. The authors of the measured heat capacity and showed that it differs significantly.