Energies and Entanglement in Multiply-coupled Phase Qubit Systems

TL;DR

This paper investigates the energy spectra and entanglement properties of three capacitively-coupled phase qubits through numerical simulations, highlighting their potential for quantum gate operations and information transmission.

Contribution

It provides new insights into the energy spectra and entanglement behavior of multi-qubit systems, extending previous studies beyond two qubits.

Findings

Identification of avoided crossings indicating entanglement

Analysis of energy spectra in different coupling configurations

Implications for quantum gate design and information transfer

Abstract

The superconducting Josephson junction has been demonstrated to be a strong candidate for building quantum bits or "qubits" which are the components of a future quantum computer. In recent years, considerable theoretical and experimental effort have been focused on studying quantum properties of single qubits and two coupled solid-state qubits. We present results of numerical simulations of the energy spectra of more three phase qubits that are capacitively-coupled in different configurations. We discuss the ensuing entanglement between component qubits as manifested in avoided crossings and how these may play a role in building gates and transmitting qubit state information.