Reservoir-Free Decoherence in Flying Qubits
arXiv:2305.02746 · doi:10.1103/PhysRevLett.132.220403
Abstract
An effective time-dependent Hamiltonian can be implemented by making a quantum system fly through an inhomogeneous potential, realizing, for example, a quantum gate on its internal degrees of freedom. However, flying systems have a spatial spread that will generically entangle the internal and spatial degrees of freedom, leading to decoherence in the internal state dynamics, even in the absence of any external reservoir. We provide formulas valid at all times for the dynamics, fidelity, and change of entropy for ballistic particles with small spatial spreads, quantified by . This non-Markovian decoherence can be significant for ballistic flying qubits (scaling as ) but usually not for flying qubits carried by a moving potential well (scaling as ). We also discuss a method to completely counteract this decoherence for a ballistic qubit later measured.
4 pages, 3 figures, plus supplemental material
References in corpus (30)
- Coherent control of an atomic collision in a cavity
- Quantum collision models: open system dynamics from repeated interactions
- Reconciliation of quantum local master equations with thermodynamics
- Coherent control of single electrons: a review of current progress
- Measurement of Time-of-Arrival in Quantum Mechanics
- Electrical control of a solid-state flying qubit
- Hong-Ou-Mandel experiment for temporal investigation of single electron fractionalization
- Identifying optimal cycles in quantum thermal machines with reinforcement-learning
- A shuttling-based two-qubit logic gate for linking distant silicon quantum processors
- Local effective dynamics of quantum systems: A generalized approach to work and heat
- Time-of-Flight Measurements of Single-Electron Wave Packets in Quantum-Hall Edge States
- Distant spin entanglement via fast and coherent electron shuttling
- Sound-driven single-electron transfer in a circuit of coupled quantum rails
- Clock-Driven Quantum Thermal Engines
- Fundamental limits on quantum dynamics based on entropy change
- Hong-Ou-Mandel characterization of multiply charged Levitons
- Coulomb-mediated antibunching of an electron pair surfing on sound
- Autonomous Maxwell's demon in a cavity QED system
- Thermalization induced by quantum scattering
- Internal decoherence in nano-object interferometry due to phonons
- Trapping and counting ballistic non-equilibrium electrons
- In-flight distribution of an electron within a surface acoustic wave
- Post-selection and quantum energetics
- Conservation laws in quantum noninvasive measurements
- Quantum Measurements, Energy Conservation and Quantum Clocks
- Perturbation Theory for Quantum Information
- Cavity QED nondemolition measurement scheme using quantized atomic motion
- Using Mathematica for Quantum Mechanics: A Student's Manual
- Towards a dephasing diode: asymmetric and geometric dephasing
- Perturbation theory of von Neumann Entropy