Creating arbitrary quantum vibrational states in a carbon nanotube

TL;DR

This paper proposes a theoretical method to generate and characterize arbitrary quantum vibrational states in a carbon nanotube resonator using spin-phonon coupling and electrical control.

Contribution

It introduces a scheme to create and analyze arbitrary phonon states in a CNT resonator via spin-based non-linearity and electrical pulses.

Findings

Demonstrates the feasibility of preparing various quantum phonon states.

Provides a protocol for Wigner tomography of phonon states.

Shows potential for quantum information processing with nanomechanical systems.

Abstract

We theoretically study the creation of single- and multi-phonon Fock states and arbitrary superpositions of quantum phonon states in a nanomechanical carbon nanotube (CNT) resonator. In our model, a doubly clamped CNT resonator is initialized in the ground state and a single electron is trapped in a quantum dot which is formed by a electric gate potential and brought into the magnetic field of a micro-magnet. The preparation of arbitrary quantum phonon states is based on the coupling between the mechanical motion of the CNT and the electron spin which acts as a non-linearity. We assume that electrical driving pulses with different frequencies are applied on the system. The quantum information is transferred from the spin qubit to the mechanical motion by the spin-phonon coupling and the electron spin qubit can be reset by the single-electron spin resonance. We describe Wigner tomography which can be applied at the end to obtain the phase information of the prepared phonon states.