# Graphane with carbon dimer defects: Robust in-gap states and a scalable two-dimensional platform for quantum computation

## TL;DR

This paper explores defect-induced in-gap states in graphane with carbon dimers, proposing a scalable, room-temperature quantum computing platform based on optical and magnetic control of localized qubits.

## Contribution

It introduces a novel defect engineering approach in graphane to create stable, controllable qubits for quantum computation.

## Key findings

- Robust in-gap defect states emerge in defective graphane.
- Multiple nondegenerate, spin-polarized defect levels are identified.
- A scalable quantum computing platform using optical and magnetic control is proposed.

## Abstract

We study the energy level structures of the defective graphane lattice, where a carbon dimer defect is created by removing the hydrogen atoms on two nearest-neighbor carbon sites. Robust defect states emerge inside the bulk insulating gap of graphane. While for the stoichiometric half-filled system there are two doubly degenerate defect levels, there are four nondegenerate and spin-polarized in-gap defect levels in the system with one electron less than half filling. A universal set of quantum gates can be realized in the defective graphane lattice, by triggering resonant transitions among the defect states via optical pulses and \emph{ac} magnetic fields. The sizable energy separation between the occupied and the empty in-gap states enables precise control at room temperature. The spatial locality of the in-gap states implies a qubit network of extremely high areal density. Based on these results, we propose that graphane as a unique platform could be used to construct the future all-purpose quantum computers.