Two-level system hyperpolarization using a quantum Szilard engine

Abstract

The innate complexity of solid state physics exposes superconducting quantum circuits to interactions with uncontrolled degrees of freedom degrading their coherence. By using a simple stabilization sequence we show that a superconducting fluxonium qubit is coupled to a two-level system (TLS) environment of unknown origin, with a relatively long energy relaxation time exceeding $50\text{ms}$. Implementing a quantum Szilard engine with an active feedback control loop allows us to decide whether the qubit heats or cools its TLS environment. The TLSs can be cooled down resulting in a four times lower qubit population, or they can be heated to manifest themselves as a negative temperature environment corresponding to a qubit population of $\sim 80\%$. We show that the TLSs and the qubit are each other's dominant loss mechanism and that the qubit relaxation is independent of the TLS populations. Understanding and mitigating TLS environments is therefore not only crucial to improve qubit lifetimes but also to avoid non-Markovian qubit dynamics.

References in corpus (38)

• Information heat engine: converting information to energy by feedback control
• Coherent Josephson qubit suitable for scalable quantum integrated circuits
• Towards understanding two-level-systems in amorphous solids -- Insights from quantum circuits
• The Kerr-Cat Qubit: Stabilization, Readout, and Gates
• Experimental realization of a Szilard engine with a single electron
• Exponential suppression of bit or phase flip errors with repetitive error correction
• Fluctuations of Energy-Relaxation Times in Superconducting Qubits
• Creation and control of multi-phonon Fock states in a bulk acoustic wave resonator
• High Kinetic Inductance Superconducting Nanowire Resonators for Circuit QED in a Magnetic Field
• Fast Reset and Suppressing Spontaneous Emission of a Superconducting Qubit
• Enhancing the Coherence of a Spin Qubit by Operating it as a Feedback Loop That Controls its Nuclear Spin Bath
• Correlated Charge Noise and Relaxation Errors in Superconducting Qubits
• Millisecond charge-parity fluctuations and induced decoherence in a superconducting qubit
• Hot non-equilibrium quasiparticles in transmon qubits
• Granular aluminum: A superconducting material for high impedance quantum circuits
• Bosonic quantum error correction codes in superconducting quantum circuits
• Quasiparticle dynamics in granular aluminum close to the superconductor to insulator transition
• Electric field spectroscopy of material defects in transmon qubits
• Origin and Suppression of $1/f$ Magnetic Flux Noise
• Suppressing relaxation in superconducting qubits by quasiparticle pumping
• Non-Poissonian Quantum Jumps of a Fluxonium Qubit due to Quasiparticle Excitations
• Quantum Error Correction with the Toric-GKP Code
• Observation of classical-quantum crossover of 1/f flux noise and its paramagnetic temperature dependence
• Two-level systems in superconducting quantum devices due to trapped quasiparticles
• Trapping a single vortex and reducing quasiparticles in a superconducting resonator
• Parity measurement in the strong dispersive regime of circuit quantum acoustodynamics
• Error-corrected gates on an encoded qubit
• Measuring the temperature dependence of individual two-level systems by direct coherent control
• Decoherence spectroscopy with individual two-level tunneling defects
• Quantum probe hyperpolarisation of molecular nuclear spins
• TLS Dynamics in a Superconducting Qubit Due to Background Ionizing Radiation
• Bogoliubov Quasiparticles in Superconducting Qubits
• Simultaneous sub-second hyperpolarization of the nuclear and electron spins of phosphorus in silicon
• Superconducting granular aluminum resonators resilient to magnetic fields up to 1 Tesla
• Quantum non-demolition dispersive readout of a superconducting artificial atom using large photon numbers
• Revealing the nonlinear response of a tunneling two-level system ensemble using coupled modes
• Acoustic spectral hole-burning in a two-level system ensemble
• Microscopic charging and in-gap states in superconducting granular aluminum

Cited by in corpus (28)

• Phonon engineering of atomic-scale defects in superconducting quantum circuits
• Stochastic thermodynamics of a quantum dot coupled to a finite-size reservoir
• Landauer Principle and Thermodynamics of Computation
• High coherence fluxonium manufactured with a wafer-scale uniformity process
• Shaping photons: quantum computation with bosonic cQED
• The Quantum House Of Cards
• Mitigating Losses of Superconducting Qubits Strongly Coupled to Defect Modes
• Granular Aluminum Parametric Amplifier for Low-Noise Measurements in Tesla Fields
• A Single-Ion Information Engine for Charging Quantum Battery
• Topological transitions in quantum jump dynamics: Hidden exceptional points
• Gatemonium: A Voltage-Tunable Fluxonium
• Compact vacuum gap transmon qubits: Selective and sensitive probes for superconductor surface losses
• Asymmetries of thermal processes in open quantum systems
• Heat bath in a quantum circuit
• Spin Environment of a Superconducting Qubit in High Magnetic Fields
• Solomon equations for qubit and two-level systems: Insights into non-Poissonian quantum jumps
• Observation of discrete charge states of a coherent two-level system in a superconducting qubit
• Characterization of drive-induced unwanted state transitions in superconducting circuits
• Thin-film quartz for high-coherence piezoelectric phononic crystal resonators
• Real-time adaptive tracking of fluctuating relaxation rates in superconducting qubits
• Sub-Harmonic Control of a Fluxonium Qubit via a Purcell-Protected Flux Line
• Exploring van der Waals cuprate superconductors using a hybrid microwave circuit
• Intermodulation spectroscopy and the nonlinear response of two-level systems in superconducting coplanar waveguide resonators
• Quantum Coherence in Superconducting Vortex States
• Heat operator approach to quantum stochastic thermodynamics in the strong-coupling regime
• Dynamic thermalization on noisy quantum hardware
• Global-Local Duality of Energetic Control Cost in Multipartite Quantum Correlated Systems
• Quantum refrigerator embedded in spin-star environments: Scalings of temperature and refrigeration time