𝔖 Bobbio Scriptorium
✦   LIBER   ✦

Singlet–triplet transition induced by Zeeman energy in weakly coupled vertical double quantum dots

✍ Scribed by Tetsuo Kodera; Keiji Ono; Shinichi Amaha; Yasuhiro Tokura; Yasuhiko Arakawa; Seigo Tarucha


Publisher
Elsevier Science
Year
2008
Tongue
English
Weight
217 KB
Volume
40
Category
Article
ISSN
1386-9477

No coin nor oath required. For personal study only.

✦ Synopsis


We use Pauli-spin blockade (P-SB) in a vertical double quantum dot to study the interplay between the nuclear spin effect and exchange interaction. We observe a specific P-SB lifting, reflecting coexistence of singlet-triplet admixing due to fluctuating nuclear spin field and singlet-triplet transition induced by the Zeeman effect when the exchange energy and the fluctuating nuclear field energy are comparable. From measurement of the Zeeman-induced P-SB lifting, we derive the exchange energy as a function of inter-dot level detuning. We confirm enhancement of exchange energy by resonance, and use Hubbard model calculation to account for it.