Gate-Defined Accumulation-Mode Quantum Dots in Monolayer and Bilayer WSe2

Signature of Spin-Resolved Quantum Point Contact in p-Type Trilayer WSe2 van der Waals Heterostructure

“…[4][5][6] Another possibility on quantum confinement in TMDC offers the confinement of optically excited quasi-particles, 7,8 and the new physics related to exciton condensation can be artificially realized like being trapped in Moiré potentials. 9,10 To date, however, the number of electrostatically induced quantum confinement devices in TMDC or similar 2D materials 7,[11][12][13][14][15][16][17][18] was limited due to their poor crystal quality, mobility, ambient stability, and contact properties. Various methods such as doped or gated graphene contact, 7,17 phase engineering, 19,20 transferred top contact, 21,22 or bottom contact architecture [23][24][25] assembled in glove box was reliably realized for TMDC devices although the quality of low-temperature Ohmic contact is still limited.…”

Nanomaterials for Quantum Information Science and Engineering

“…2D transition metal chalcogenides are interesting for spin-valley QD qubits due to strong spin-valley coupling and valley-dependent optical selection rules [188,189] , potentially enabling spin-valley qubits with an intrinsic spin-photon interface. Despite single-particle level transport having been demonstrated in gate-defined TMD QDs [190,191,582] , the readout and coherence times of spin/valley states in these devices has not been demonstrated yet, likely due to high contact resistance at low temperatures. Moreover, mobilities lower than graphene and conventional QD materials makes it difficult to confine individual carriers electrostatically; other means of confinement may be explored.…”

“…Gate-defined QDs have been demonstrated in WSe2 [190,191] , WS2 [192] , and MoS2 [193][194][195] monolayers and MoS2 nanotubes [196] . Fig 4c depicts an example of a gate-defined QD in WSe2 sandwiched between layers of hBN.…”

“…Like in graphene, moiré potentials formed in twisted bilayers of TMDs or TMD heterostructures offer another route to charge confinement in TMDs. [199] [191] with permission from American Physical Society.…”

Gate controlled quantum dots in monolayer WSe2

“…Moreover, they have potential for realizing spin qubits with long coher-ence time due to spin-valley locking, caused by the strong spin-orbit interaction and the symmetries of their 2D lattice 16 . These promising properties motivated recent efforts to understand charge transport through quantum dots in 2D materials [17][18][19][20][21] . Gated structures were used to create many-electron single and double quantum dots in eight layers of molybdenum disulfide (MoS 2 ) 18 , in monolayer MoS 2 19 , as well as in monolayer and bilayer tungsten diselenide (WSe 2 ) 21 .…”