Evidence for melting of HD and D2 clusters in solid neon below 1 K

Abstract

We report on an electron spin resonance study of H and D atoms stabilized in solid mixtures of neon, molecular deuterium and hydrogen deuteride. We observed that H and D atoms can be stabilized in pure HD and D2 clusters formed in pores of solid Ne as well as in a Ne environment. Raising temperature from 0.1 to 1.3 K results in a rapid recombination of a significant fraction of both H and D atoms in HD and D2 clusters. The recombination rate appears to be five and seven orders of magnitude faster than in solid bulk samples of HD and D2, respectively. We explain this recombination rate enhancement by melting of clusters of molecular hydrogen isotopes, similar to what has been observed for atomic hydrogen in H2 clusters [Sheludiakov et al. Phys. Rev. B 97, 104108 (2018)]. Our observations do not provide evidence for a superfluid behavior of these clusters at temperatures of 0.1-1.3 K.

Single electrons on solid neon as a solid-state qubit platform

“…Second, residual roughness of the Ne surface may cause extra scattering to the electron motion. Improvement to the device design and Ne growth process 55 , and operation at the charge noise "sweet spot" are expected to mitigate these decoherence issues. It has been theoretically calculated that the in-plane motional coherence of an electron on solid Ne surface can be several milliseconds 61 .…”

“…It has been theoretically calculated that the in-plane motional coherence of an electron on solid Ne surface can be several milliseconds 61 . Ultimately, utilizing the spin states through engineered spin-orbital coupling 16,20,52 can yield ultralong qubit coherence in excess of 1 s 52,[54][55][56] .…”

“…Without optimization, the measured T 1 = 15 µs and T 2 200 ns have already reached the state of the art for a charge qubit 51 , highlighting the promise of this new material environment. With projected development employing spin-charge conversion 16,20,52 , we anticipate the nearly perfect spinless environment formed by solid neon 53 to support electron spin qubits with estimated coherence time over 1 s 52,[54][55][56] . Beyond quantum computing, this novel solid-state single-electron qubit platform creates an appealing hybrid quantum framework that can connect various qubit platforms, thereby paving new pathways in quantum information science and technology.…”