Configuring Electronic States in an Atomically Precise Array of Quantum Boxes

Abstract

A 2D array of electronically coupled quantum boxes is fabricated by means of on-surface self-assembly assuring ultimate precision of each box. The quantum states embedded in the boxes are configured by adsorbates, whose occupancy is controlled with atomic precision. The electronic interbox coupling can be maintained or significantly reduced by proper arrangement of empty and filled boxes.

Adsorbate-Induced Modification of the Confining Barriers in a Quantum Box Array

“…This is in agreement with Ref. 48 , in which the effective mass of the surface state upon metal-organic network formation on Cu(111) changed from m* = 0.43 ± 0.01 m e to m* = 0.57 ± 0.02 m e (state below the Fermi level). In our study, due to the intrinsically reduced intensity above the Fermi level, the uncertainty in determining m* is significantly higher (± 0.11 m e ), therefore we cannot exclude a small change in m* for our QBS, i.e.…”

Effective determination of surface potential landscapes from metal-organic nanoporous network overlayers

“…In figure 3(a), the second derivative of the experimental data (raw data in figure S2) exhibits the expected shallow dispersive bands of QD arrays [20,22,23,27]. The lower energy band corresponding to n=1 PLS has a ∼80meV bandwidth and shifts ∼150meV towards E F with respect to the pristine Cu SS and increases m * to~m 0.58 0 [20,23,32]. This effective mass is higher than the 2DEG reference as a result of the confinement induced by the nanoporous network [23,37], which is certainly substantial judging from the prominent energy gap (120 ± 30 meV) detected at the zone boundaries (M point) separating the n=1 and n=2 PLS bands [42].…”

“…The organometallic network that we study is formed by deposition of the organic dye DPDI (4,9diaminoperylene quinone-3,10-diimine), which undergoes a dehydrogenation process when deposited on Cu(111) and heated to 250°C. The resulting organic building block 3deh-DPDI is an 'exo-ligand' coordinated to Cu adatoms that forms a long-range ordered, commensurate MONN [20,22,[29][30][31][32][33]36]. The unit cell is composed of 3 molecules and 6 Cu adatoms.…”

“…This raises the question whether such (to some extent arbitrary) assumptions are necessary when simulating the electron confinement by these MONNs. Here, we address this question by studying in detail the interaction between the 3deh-DPDI network [20,22,25,[29][30][31][32][33] and the Cu(111) 2DEG. Based on a combination of scanning tunneling microscopy and spectroscopy (STM and STS), angle-resolved photoemission (ARPES) and Kelvin probe force microscopy (KPFM) measurements, together with EPWE simulations, we demonstrate that both local confinement effects and the emergence of electronic bands induced by interpore coupling can be satisfactorily reproduced.…”

Tunable Flat Band in Large‐Scale Kagome Lattice of Single Layer (BETS)2GaCl4

“…For example, in a frustrated system such as Kagome lattice, when hopping is restricted to the nearest neighbors only, the electron wave functions cancel each other due to destructive interference, thus localizing the electrons within the hexagonal units . The electron localization in a flat band system is very different from that due to spatial confinement within potential wells such as encapsulating molecules into quantum boxes . Electrons on a flat band system are very sensitive to external perturbations which offer the opportunity to test a variety of correlated phenomena including spin liquid, unconventional superconductivity, and ferromagnetism.…”