Readout of Majorana Qubits

Abstract

Schemes for topological quantum computation with Majorana bound states rely heavily on the ability to measure products of Majorana operators projectively. Here, we employ Markovian quantum measurement theory, including the readout device, to analyze such measurements. Specifically, we focus on the readout of Majorana qubits via continuous charge sensing of a tunnel-coupled quantum dot by a quantum point contact. We show that projective measurements of Majorana products ${\prod }_i{\hat{\gamma }}_i$ can be implemented by continuous charge sensing under quite general circumstances. Essential requirements are that a combined local parity $\hat{\pi }$, involving the quantum dot charge along with the Majorana product of interest, be conserved, and that the two eigenspaces of the combined parity $\hat{\pi }$ generate distinguishable measurement signals. We find that qubit readout may have to rely on measuring noise correlations of the quantum-point-contact current. The average current encodes the qubit readout only transiently for fine-tuned parameters or in the presence of relaxation processes. We also discuss the corresponding measurement and decoherence times and consider processes such as residual Majorana hybridizations which are detrimental to the measurement protocol. Finally, we emphasize that the underlying mechanism -- which we term symmetry-protected readout -- is quite general and has further implications for both, Majorana and non-Majorana systems.

arXiv comment15 pages, 11 figures, Appendix: 13 pages, 2 figures

References in corpus (41)

• Fault-tolerant quantum computation by anyons
• Non-Abelian Anyons and Topological Quantum Computation
• Majorana Fermions and a Topological Phase Transition in Semiconductor-Superconductor Heterostructures
• Helical liquids and Majorana bound states in quantum wires
• Cavity quantum electrodynamics for superconducting electrical circuits: an architecture for quantum computation
• Non-Abelian statistics and topological quantum information processing in 1D wire networks
• Realizing Majorana zero modes in superconductor-semiconductor heterostructures
• Scalable Designs for Quasiparticle-Poisoning-Protected Topological Quantum Computation with Majorana Zero Modes
• Milestones toward Majorana-based quantum computing
• Symmetries and conserved quantities in Lindblad master equations
• Electron Teleportation via Majorana Bound States in a Mesoscopic Superconductor
• Continuous quantum measurement of a double dot
• Majorana qubit decoherence by quasiparticle poisoning
• Majorana box qubits
• Non-Abelian operations on Majorana fermions via single charge control
• Continuous quantum measurement of two coupled quantum dots using a point contact: A quantum trajectory approach
• Analysis of quantum semigroups with GKS--Lindblad generators II. General
• Roadmap to Majorana surface codes
• Dynamics of a mesoscopic qubit under continuous quantum measurement
• Decay rates for topological memories encoded with Majorana fermions
• Majorana Fermion Surface Code for Universal Quantum Computation
• Universal Quantum Computation with Hybrid Spin-Majorana Qubits
• Topological quantum computation away from the ground state with Majorana fermions
• Dephasing of Majorana-based qubits
• Decoherence of Majorana qubits by noisy gates
• Quantum Computing with Majorana Fermion Codes
• Spin-dependent coupling between quantum dots and topological quantum wires
• Controlled-NOT for multiparticle qubits and topological quantum computation based on parity measurements
• Dephasing and leakage dynamics of noisy Majorana-based qubits: Topological versus Andreev
• Parity-to-charge conversion in Majorana qubit readout
• Fermion parity measurement and control in Majorana circuit quantum electrodynamics
• Majoranas in Noisy Kitaev Wires
• Readout of Majorana parity states using a quantum dot
• Parity-to-charge conversion for readout of topological Majorana qubits
• Microwave readout of Majorana qubits
• Four-Majorana qubit with charge readout: dynamics and decoherence
• Majorana Qubit Readout Using Longitudinal Qubit-Resonator Interaction
• Hypothesis testing with open quantum systems
• Ubiquitous non-local entanglement with Majorana bound states
• Fidelity and visibility reduction in Majorana qubits by entanglement with environmental modes
• Transport Signatures of a Majorana Qubit and Read-out-induced Dephasing

Cited by in corpus (36)

• Universality of entanglement transitions from stroboscopic to continuous measurements
• Majorana nanowires for topological quantum computation
• Topological transitions with continuously monitored free fermions
• Hunting for Majoranas
• Roadmap towards Majorana qubits and nonabelian physics in quantum dot-based minimal Kitaev chains
• Parity-to-charge conversion in Majorana qubit readout
• Colloquium: Quantum Properties and Functionalities of Magnetic Skyrmions
• Dispersive readout of Majorana qubits
• Recent progress on Majorana in semiconductor-superconductor heterostructures--Engineering and detection
• Charge noise and overdrive errors in reflectometry-based charge, spin and Majorana qubit readout
• Braiding-based quantum control of a Majorana qubit built from quantum dots
• Demonstrating Majorana non-Abelian properties using fast adiabatic charge-transfer
• Detecting Majorana modes by readout of poisoning-induced parity flips
• Dynamical leakage of Majorana mode into side-attached quantum dot
• Fermion-Parity-Based Computation and its Majorana-Zero-Mode Implementation
• Visibility of noisy quantum dot-based measurements of Majorana qubits
• Interference and parity blockade in transport through a Majorana box
• Multi-level effects in quantum-dot based parity-to-charge conversion of Majorana box qubits
• Holonomic implementation of CNOT gate on topological Majorana qubits
• Readout of Majorana bound states via Landau-Zener transition
• Subgap states in semiconductor-superconductor devices for quantum technologies: Andreev qubits and minimal Majorana chains
• Implementation of single-qubit gates via parametric modulation in the Majorana transmon
• Bath-induced decoherence in finite-size Majorana wires at non-zero temperature
• Direct visualization of quasiparticle concentration around superconducting vortices
• Probing the non-Abelian fusion of a pair of Majorana zero modes
• Physics of the Majorana-superconducting qubit hybrids
• Distinguishing Majorana bound states from Andreev bound states through differential conductance and current noise spectrum
• Spin-Exchange Induced Spillover on Poor Man's Majoranas in Minimal Kitaev Chains
• Majorana bound state parity exchanges in planar Josephson junctions
• Transport-based fusion that distinguishes between Majorana and Andreev bound states
• Transport and fusion of Majorana zero modes in the presence of nonadiabatic transitions
• Non-Abelian holonomy of Majorana zero modes coupled to a chaotic quantum dot
• Robustness of a state with Ising topological order against local projective measurements
• Noise as a probe of Majorana fermion surface states
• Majorana qubit readout by a point-contact detector under finite bias voltages
• Parity readout in Majorana box qubits from the dispersive to the resonant regime