A gentle touch for better control, a quantum mechanical con, and milestone PRL papers

Evidence for a New Phase of Solid He3
D. D. Osheroff, R. C. Richardson, and D. M. Lee
Phys. Rev. Lett. 28, 885 (1972)

New Magnetic Phenomena in Liquid He3 below 3 mK
D. D. Osheroff, W. J. Gully, R. C. Richardson, and D. M. Lee
Phys. Rev. Lett. 29, 920 (1972)

Osheroff, Richardson, and Lee were looking for a phase transition to a kind of magnetic order in solid helium-3 at very low temperatures. They were achieving these temperatures by using what was called "Pomeranchuk cooling" -- putting pressure on a mixture of solid and liquid helium-3. In the first Letter two anomalies in the measurement were interpreted as phase transitions in solid helium-3. But because of uncertainties in the interpretation the authors used a crude version of what later was named "magnetic resonance imaging" to determine that the anomalies were in the liquid. Other measurements led to the conclusion that they had in fact discovered superfluid helium-3. An important element in this interpretation was the theoretical work of Leggett (see following Milestone). For this research Osheroff, Richardson, and Lee received the 1996 Nobel Prize in Physics "for the discovery of superfluid helium-3".

Interpretation of Recent Results on He3 below 3 mK: A New Liquid Phase?
A. J. Leggett
Phys. Rev. Lett. 29, 1227 (1972)

Leggett describes in his Nobel lecture how he interrupted a holiday (because it rained on that day!) to meet with Robert Richardson at Leggett's office in Sussex. Richardson described the experimental results on phase transitions in liquid He3, which set Leggett into deep thought on their theoretical explanation. This Letter presents the foundation for understanding the properties of these complex superfluid phases. Many others contributed to that understanding as well, but Leggett was credited with the complete theoretical underpinning. A. A. Abrikosov, V. L. Ginzburg, and A. J. Leggett were awarded the 2003 Nobel Prize in Physics "for pioneering contributions to the theory of superconductors and superfluids." See also Leggett's Nobel Lecture [Rev. Mod. Phys. 76, 999 (2004)], and the Nobel Focus story Phys. Rev. Focus 12, story 16.