Assessing the quantumness of a damped two-level system

Abstract

We perform a detailed analysis of the nonclassical properties of a damped two-level system. We compute and compare three different criteria of quantumness, the $l_1$-norm of coherence, the Leggett- Garg inequality and a quantum witness based on the no-signaling in time condition. We show that all three quantum indicators decay exponentially in time as a result of the coupling to the thermal reservoir. We further demonstrate that the corresponding characteristic times are identical and given by the coherence half-life. These results quantify how violations of Leggett-Garg inequalities and nonzero values of the quantum witness are connected to the coherence of the two-level system.

8 pages, 6 figures

References in corpus (8)

• Significant-loophole-free test of Bell's theorem with entangled photons
• Measuring Quantum Coherence with Entanglement
• Witnessing Quantum Coherence: from solid-state to biological systems
• Ideal negative measurements in quantum walks disprove theories based on classical trajectories
• Opening up the Quantum Three-Box Problem with Undetectable Measurements
• Violation of the Leggett-Garg Inequality in Neutrino Oscillations
• A strict experimental test of macroscopic realism in a superconducting flux qubit
• A scattering quantum circuit for measuring Bell's time inequality: a nuclear magnetic resonance demonstration using maximally mixed states

Cited by in corpus (16)

• Coherence and non-classicality of quantum Markov processes
• Validating and controlling quantum enhancement against noise by motion of a qubit
• Quantumness and memory of one qubit in a dissipative cavity under classical control
• Quantum Thermodynamics for Driven Dissipative Bosonic Systems
• Experimental violations of Leggett-Garg's inequalities on a quantum computer
• Influence of equilibrium and nonequilibrium environments on macroscopic realism through the Leggett-Garg inequalities
• Enhanced violation of Leggett-Garg Inequality in three flavour neutrino oscillations via non-standard interactions
• Macroscopic realism of quantum work fluctuations
• Enhancing violations of Leggett-Garg inequalities in nonequilibrium correlated many-body systems by interactions and decoherence
• Quantumness and speedup limit of a qubit under transition frequency modulation
• The Leggett-Garg inequalities and the relative entropy of coherence in the Bixon-Jortner model
• Tailoring the quantumness of a driven qubit
• Violations of the Leggett-Garg inequality for coherent and cat states
• Leggett-Garg inequalities for multitime processes
• Assessing the quantumness of the annealing dynamics via Leggett Gargs inequalities: a weak measurement approach
• Leggett-Garg inequalities with deformed Pegg-Barnett phase observables