Single- and Few-Electron States in Deformed Topological Insulator Quantum Dots

We theoretically investigate the single- and few-electron states in deformed HgTe quantum dots （QDs） with an inverted band structure using the full configuration interaction method. For the circular and deformed QD, it is found that the energy of edge states is robust against the shape from the circular QD in various elliptic ones. For the few electron states, electrons will firstly fill the edge states localized at the short axis, then the states localized at the long axis of the QD before filling the bulk states. The filling of the edge states can be controlled by tuning the dot size or the deformation of the geometry of the HgTe QD, respectively.

Solid-state quantum computation station

Solid-state quantum computation station belongs to the group 2 of manipulation of quantum state in the Synergetic Extreme Condition User Facility. Here we will first outline the research background, aspects, and objectives of the station, followed by a discussion of the recent scientific as well as technological progress in this field based on similar experimental facilities to be constructed in the station. Finally, a brief summary and research perspective will be presented.

Topological phases and type-II edge state in two-leg-coupled Su-Schrieffer-Heeger chains

Topological quantum states have attracted great attention both theoretically and experimentally.Here,we show that the momentum-space lattice allows us to couple two Su-Schrieffer-Heeger(SSH)chains with opposite dimerizations and staggered interleg hoppings.The coupled SSH chain is a four-band model which has sublattice symmetry similar to the SSH4.Interestingly,the topological edge states occupy two sublattices at the same time,which can be regarded as a one-dimension analogue of the type-II corner state.The analytical expressions of the edge states are also obtained by solving the eigenequations.Finally,we provide a possible experimental scheme to detect the topological winding number and corresponding edge states.

Simulating a topological transition in a superconducting phase qubit by fast adiabatic trajectories

The significance of topological phases has been widely recognized in the community of condensed matter physics. The well controllable quantum systems provide an artificial platform to probe and engineer various topological phases. The adiabatic trajectory of a quantum state describes the change of the bulk Bloch eigenstates with the momentum, and this adiabatic simulation method is however practically limited due to quantum dissipation. Here we apply the "shortcut to adiabaticity"(STA) protocol to realize fast adiabatic evolutions in the system of a superconducting phase qubit. The resulting fast adiabatic trajectories illustrate the change of the bulk Bloch eigenstates in the Su-Schrieffer-Heeger(SSH) model. A sharp transition is experimentally determined for the topological invariant of a winding number. Our experiment helps identify the topological Chern number of a two-dimensional toy model, suggesting the applicability of the fast adiabatic simulation method for topological systems.