Triplet-blockaded Josephson supercurrent in double quantum dots

Subgap Dynamics of Double Quantum Dot Coupled Between Superconducting and Normal Leads

“…In particular, for the singly occupied quantum dots (what can be assured by appropriate gating) the superconducting proximity effect could be blocked. Such triplet blockade effect has been recently reported in S-DQD-S 17 and N-DQD-S 18 nanostructures. As regards the Coulomb potential, its influence is indirectly manifested through the singlet-doublet transitions (related to variations between the even-odd occupancies of the quantum dots 17,18 ) and, under specific conditions, can lead to the subgap Kondo effect 22,23,30,38,44 .…”

Transient effects in double quantum dot sandwiched laterally between superconducting and metallic leads

“…In particular, we reveal that the leakage of Cooper pairs onto both quantum dots would be blocked whenever the dots are initially singly occupied by the same spin electrons. This 'triplet/Andreev blockade' has been recently observed experimentally under the stationary conditions, using DQD in the Josephson (S-DQD-S) [16] and Andreev (N-DQD-S) junctions [17]. To get a deeper insight into the dynamical behavior in the considered N-DQD-S setup, we analyze in detail various timedependent quantities taking into account several initial configurations.…”

“…In the N-DQD-S junctions similar blockade is still present, although in less severe version because electrons can flow back and forth to/from the normal lead. Under the stationary conditions such triplet-blockade has been reported experimentally in the Josephson (S-DQD-S) junction [16] and its analogue, so called Andreevblockade, has been recently evidenced for N-DQD-S heterostructure [17]. Suppression of the superconducting proximity effect occurs also in presence of the correlations, especially in the weak interdot coupling regime.…”

“…Since double quantum dot (DQD) configurations provide a versatile platform for the implementation of quantum information processing [10,11], such systems have also been considered in hybrid setups involving superconducting elements. Experimentally, their bound states have been probed by the tunneling spectroscopy, using InAs [12][13][14][15][16][17], InSb [18], Ge/Si [19] quantum dots or carbon nanotubes [20,21] contacted with superconducting lead(s), as well as by the scanning tunneling microscopy (STM) applied to the magnetic dimers deposited on su-perconducting substrates [6,[22][23][24]. The single V, Cr, Mn, Fe, and Co atoms deposited on aluminum have revealed that Cr and Mn atoms have contributions from different orbitals to subgap quasiparticles, whereas the other elements merely consist of one pair of the in-gap bound states [25].…”

Symmetry-controlled singlet-triplet transition in a double-barrier quantum ring

“…It is also important for developing a microscopic understanding what role magnetic impurities play in electron transport [4]. Configurations involving several spins, such as spin-singlet and triplet states, have provided new ways to operate spin qubits [5][6][7], and to gain new insight to, for example, quantum criticality [8], and Cooper pair transport in Josephson junctions [9,10].…”