Atomtronic superconducting quantum interference device in synthetic dimensions

Abstract

Coherence and scalability are essential properties of quantum systems required in quantum computers. This study presents a high coherent and scalable qubit system with atomtronics in synthetic dimensions. It is atomtronic counterpart of superconducting quantum interference device. Comparing with traditional superconducting quantum interference device which requires at least $2$-dimensional circuits, the synthetic dimensional superconducting quantum interference device can be realized only in $1$-dimensional circuits. The synthetic dimensional system is composed of Bose-Einstein condensate in two neighboring optical wells which is coupled to an external coherent light. Control parameter for the qubit is naturally provided by artificial magnetic flux originated from the coherent atom-light coupling. It should be a great advantage for the scalability and integration feature of quantum logic gates.

Figures (3)

• Figure 1: (Color on line) (a) Schematic illustration of BEC ring in synthetic dimensions. (b) Atomtronic Josephson junction in position space. (c) Atomtronic Josephson junction in atom internal states. (d) Atomtronic SQUID in synthetic dimensions.
• Figure 2: (Color on line) Atom current as a function of control phase $\phi$. Rectangular dot black line: $\theta_{0}=\theta_{1}=\theta_{g}=0$. Circle dot red line: $\theta_{0}=0.1$, $\theta_{1}=0.05$ and $\theta_{g}=0.01$. Up triangle dot blue line: $\theta_{0}=0.3$, $\theta_{1}=-0.5$ and $\theta_{g}=0.1$. Down triangle dot green line: $\theta_{0}=-0.1$, $\theta_{1}=0.9$ and $\theta_{g}=0.7$.
• Figure 3: (Color on line) (a) Potential energy versus phase $\theta$. Here, $U/\hbar=10J$. (b) Comparison between the original potential and quadratic order potential with respect to $U/\hbar=10J$. (c) Frequency of the harmonic oscillator defined in Eq.\ref{['eq:Ham-quant']}.