arXiv subjects

Akio Higo

Publications and source records attributed to Akio Higo.

3 recordsLinked to original sources

arXiv2023

Experimental demonstration of position-controllable topological interface states in high-frequency topological integrated circuits

Topological integrated circuits are integrated-circuit realizations of topological systems. Here we show an experimental demonstration by taking the case of the Kitaev topological superconductor model. An integrated-circuit implementation enables us to realize high resonant frequency as high as 13GHz. We explicitly observe the spatial profile of a topological edge state. In particular, the topological interface state between a topological segment and a trivial segment is the Majorana-like state. We construct a switchable structure in the integrated circuit, which enables us to control the position of a Majorana-like interface state arbitrarily along a chain. Our results contribute to the development of topological electronics with high frequency integrated circuits.

cond-mat.mes-hall↗

arXiv2022

Universal quantum computer based on Carbon Nanotube Rotators

We propose a universal quantum computer based on a chain of carbon nanotube rotators where one metallic plate is attached to each rotator. The dynamical variable is the rotational angle $ϕ$. The attached plate connected to ground electrostatically interacts with two fixed plates. Two angle positions $ϕ=0,π$ are made stable by applying a voltage difference between the attached plate and the two fixed plates. We assign $ϕ=0$ and $π$ to the qubit states $|0\rangle$ and $|1\rangle $. Then, considering a chain of rotators, we construct the arbitrary phase-shift gate, the NOT gate and the Ising gate, which constitute a set of universal quantum gates. They are executed by controlling the voltage between various plates.

quant-ph↗

arXiv2022

Universal quantum computation based on Nano-Electro-Mechanical Systems

We propose to use a buckled plate as a qubit, where a double-well potential is mechanically produced by pushing the plate from both the sides. The right and left positions of the plate are assigned to be quantum states $|0\rangle $ and $|1\rangle $. Quantum effects emerge when the displacement is of the order of picometers, although the size of a buckled plate is of the order of $1μm$. The NOT gate is executed by changing the buckling force acting on the plate, while the Pauli-Z gate and the phase-shift gate are executed by applying electric field. A two-qubit phase shift gate is materialized with the use of an electrostatic potential. They constitute a set of universal quantum gates. An examination of material parameters leads to a feasibility of a NEMS(Nano-Electro-Mechanical System)-based quantum computer.

quant-ph↗