Unexpectedly rapid 19F spin-lattice relaxation in CaF2 below 1 K

Abnormal difference between the mobilities of left- and right-twisted conformations of C6H12N2 roto-symmetrical molecules at very low temperatures

We report an abnormal difference of low-temperature mobility of left-twisted and right-twisted conformations of roto symmetric molecules C6H12N2 (dabco) located in the same positions in crystal Zn2(C8H4O4)2⋅C6H12N2. The difference between (1)H NMR (Nuclear Magnetic Resonance) spin-relaxation data for left-twisted and right-twisted molecules reaches ∼3 × 10(3) times at 8 K and tends to grow at lower temperatures. We argue that taking into account four-component relativistic Dirac wave functions in the vicinity of the nodal plane of dabco molecules and vacuum fluctuations due to virtual particle-antiparticle pairs can explain the changes which C6H12N2 conformations undergo at low temperatures.

Nanoscale torsional resonator for polarization and spectroscopy of nuclear spins

We propose a torsional resonator that couples to the transverse spin dipole of an attached sample. The absence of relative motion eliminates a source of friction that would otherwise hinder nanoscale implementation. Enhanced spontaneous emission induced by the resonator relaxes the longitudinal spin dipole at a rate of ∼1  s⁻¹ in the low-temperature limit. With signal averaging, single-proton magnetic resonance spectroscopy appears feasible at ∼10  mK and a high magnetic field, while single-shot sensitivity is practical for samples with at least tens of protons in a volume of ∼5  nm³.

Sixty Years of Nuclear Moments

In keeping with the tradition of prefatory articles for the Annual Review of Physical Chemistry, this is an autobiographical essay describing my scientific career. I begin with my background and education at Dartmouth and Caltech and follow with my half-century of research and teaching at MIT. I emphasize subjects that I found especially interesting or important, including average Hamiltonians and the beginnings of high-resolution nuclear magnetic resonance (NMR) in solids, broadband spin decoupling in liquids, NMR at milli-Kelvin temperatures, and the exploration of basic physical principles by computer. Throughout I recall with affection my mentors, colleagues, and students.