Magnetic state

Figure A2.1.11. Magnetic cooling isothemial magnetization at 4 K followed by adiabatic demagnetization to 0.04 K. (Constructed for a hypothetical magnetic substance with two magnetic states with an energy...

In NMR spectroscopy the precise energy differences between such nuclear magnetic states are of interest. To measure these differences, electromagnetic waves in the radiofrequency region (1-600 MHz) are applied, and the frequency at which transitions occur between the states, is measured. At resonance the condition... 

Anderson PW. 1961. Localized magnetic states in metals. Phys Rev 124 41-53. 

Figure 2.13 The first 2" magnetic states of the system are assigned to combinations of n qubits. The rest of the spectrum is outside of the computational basis.

Considering any of these paradigms, a minimal goal for toy models would be to manipulate the quantum dynamics of a small number of spin levels , and that requires a known and controlled composition of the wavefunction, sufficient isolation and a method for coherent manipulation. As illustrated in Figure 2.13, the first few magnetic states of the system are labelled and thus assigned qubit values. The rest of the spectrum is outside of the computational basis, so one needs to ensure that these levels are not populated during the coherent manipulation. 

Figure 6.5 Evolution of the lowest magnetic states of Dy3 complex with applied magnetic field, simulated for J = -0.6 cm-1 (a) H is applied in the Dy3 plane. Reproduced from Ref. [67] with permission from the Centre National de la Recherche Scientifique (CNRS) and The Royal Society of Chemistry ...

Lanthanide ions offer several salient properties that make them especially attractive as qubit candidates (i) their magnetic states provide proper definitions of the qubit basis (ii) they show reasonably long coherence times (iii) important qubit parameters, such as the energy gap AE and the Rabi frequency 2R, can be chemically tuned by the design of the lanthanide co-ordination shell and (iv) the same molecular structure can be realized with many different lanthanide ions (e.g. with or without nuclear spin), thus providing further versatility for the design of spin qubits or hybrid spin registers. 

A feature of the transition-metal ions, especially noticeable in the 3d series, is that many ions have two different magnetic states, which is considered to be due to... 

Fig. 16.2 A simplified scheme of the trNOE concept. The ligand L in the free state has negligible cross-relaxation between protons Hi and H2 because of its rapid tumbling motion. Upon binding to the much slower tumbling protein 7 becomes effective and leads to a transfer of magnetization from Hn to H2. Because of the dynamic equilibrium the ligand is released back into solution where it is still in the magnetization state corresponding to the bound form. The same concept is also applicable to trCCR and trRDC (see Sects. 16.4 and 16.5).

Values of the Saturation Magnetisation, 0 Multiple Magnetic States... 

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