Majorana qubit readout using longitudinal qubit-resonator interaction

Abstract

We propose a quantum non-demolition Majorana qubit readout protocol based on parametric modulation of a longitudinal interaction between a pair of Majorana bound states and a resonator. The interaction can be modulated through microwave frequency gate-voltage or flux control of a tunable tunnel barrier. The qubit-resonator coupling is quantum non-demolition to exponential accuracy, a property inherited from the topological nature of the Majorana zero modes. The same mechanism as used for single-qubit readout can also be extended to perform multi-qubit measurements and be used to enact long range entangling gates. arXiv:1809.07776v2 [quant-ph]

Parity-to-charge conversion in Majorana qubit readout

“…One could use our framework to model the effect of dispersive readouts of Majorana qubits [18,99]. To that end, we consider the electromagnetic environment shown in Fig.…”

Multilevel effects in quantum dot based parity-to-charge conversion of Majorana box qubits

“…Most of the above cited proposals are based on hybrid semiconductorsuperconductor platforms, where the Majorana modes are fixed to specific locations, such as, e.g., the ends of topological superconducting wires [1][2][3][4]. Among many suggested readout methods [25][26][27][28][29][30][31][32][33], this allows for what we call parity-to-charge conversion [19,23,26,[30][31][32][34][35][36]: a readout protocol translating the non-local parity of a Majorana pair into a local charge or current, via a suitable coupling to the Majoranas.…”

Visibility of noisy quantum dot-based measurements of Majorana qubits

“…Moreover, as physically moving MZMs [27] currently appears to be practically challenging, measurement-based schemes [28,29] come to the forefront as the most likely means of operating a Majorana-based topological quantum computer. Various theoretical proposals for Majorana qubits and their readout procedure have been put forward [30][31][32][33][34][35][36][37]. Here we concentrate on the design for the qubit that features a superconducting island in the Coulomb blockaded regime [33,34] consisting of two or more one-dimensional topological superconductors -realized for example in proximitized semiconductor nanowires [38,39] -connected by a trivial superconductor.…”