Oxides: An answer to the qubit problem?

Abstract

Low-dimensional complex oxides offer new opportunities for small-scale electronic devices where diverse spin, charge and orbital correlations can be suitably adapted by manipulating many-body interactions, geometries, disorder, fields, strain, etc. Therefore, oxides may be viewed as one of the promising candidates for replacing semiconductors in future devices. Maintaining coherence and control in a qubit is an important necessity for quantum computation. In this review, we discuss an example of oxide devices: decoherence-free oxide-based qubits. We present recent progress in demonstrating that long coherence times can be achieved at easily accessible temperatures in charge qubits of oxide double quantum dots. For treating strong coupling to the environment, we describe a nonperturbative approach that is useful for oxides. We illustrate ways to enhance the coherence times: increasing the electron–phonon coupling, detuning the dots to a fraction of the optical phonon energy, decreasing the temperature or reducing the adiabaticity.