Exploring quantum magnetism using molecules, magnetic fields and pressure.

Low-dimensional magnets can be constructed from transition-metal ions and molecular building blocks to create near ideal realizations of model quantum systems. The advantages to this approach include an enhanced capability for making adjustments to the crystal structure via chemical and applied pressure, as well as an ability to set the magnetic energy scales to levels that can be matched in the laboratory. In this way it is possible to tune interaction strengths, adjust anisotropy, cross phase boundaries and explore the predictions of quantum theory. Nevertheless, perturbing these “low-energy” systems still requires the deployment of specialist experimental techniques that allow magnetic measurements to take place in ultra-high magnetic fields and pressures in the gigapascal range. Here I will describe these techniques and show how the combination of these extreme conditions and the versatility of coordination chemistry is used to manufacture, characterise and perturb a variety of S = 1/2 antiferromagnets of different dimensionalities based on molecular-bridged networks of magnetic Cu(II) ions.