Dimers in two-dimensional He-3-He-3 mixtures

Ground-stale properties of two-dimensional He-3-He-4 mixtures art studied a t zero temperature. A general argument based on the long-ranged attraction of the phonon exchange is given for the existence of He-3 dimers in low-con centration mixtures with He-4. The binding energy of dimers ranges from mil li-to microkelvins with increasing He-4 density. By comparing the He-3 impu rity chemical potential in He-3 with the one in pure He-3 we conclude that at finite pressures He-3 dimers form a mixture with He-4 with a maximum sol ubility of similar to 3%.