Publications by authors named "Zehang Bao"
The spectral form factor (SFF) captures universal spectral fluctuations as signatures of quantum chaos, and has been instrumental in advancing multiple frontiers of physics including the studies of black holes and quantum many-body systems. The measurement of the SFF in many-body systems is however challenging due to the difficulty in resolving level spacings that become exponentially small with increasing system size. Here, we utilize the random measurement toolbox to perform a direct experimental measurement of the SFF, and hence probe the presence or absence of chaos in quantum many-body systems on superconducting quantum processors.
View Article and Find Full Text PDFTracking the time evolution of a quantum state allows one to verify the thermalization rate or the propagation speed of correlations in generic quantum systems. Inspired by the energy-time uncertainty principle, bounds have been demonstrated on the maximal speed at which a quantum state can change, resulting in immediate and practical tasks. Based on a programmable superconducting quantum processor, we test the dynamics of various emulated quantum mechanical systems encompassing single- and many-body states.
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- Non-equilibrium quantum transport is essential for advancing technologies like nanoelectronics and thermal management, focusing on energy and particle transfer through quantum channels.
- Using a superconducting quantum processor, researchers demonstrated non-equilibrium steady quantum transport by creating "baths" with qubit ladders, showing that particle currents were consistent regardless of how the baths were initialized.
- This study provides experimental support for theories in statistical mechanics and prethermalisation, while also allowing precise control over variables that affect steady currents, opening new avenues for exploring quantum transport in complex quantum systems.
Article Synopsis
- Topologically ordered phases of matter go beyond traditional theories of symmetry-breaking, exhibiting unique traits like long-range entanglement and resilience to local changes.
- The research focuses on observing a prethermal topologically ordered time crystal using superconducting qubits in a square lattice that are periodically driven, revealing new dynamics not seen in thermal equilibrium.
- Findings include identifying discrete time-translation symmetry breaking and demonstrating the connection to topological order through measuring topological entanglement entropy, showcasing the potential for exploring novel phases of matter with quantum processors.
Article Synopsis
- GHZ states, also known as two-component Schrödinger cats, are essential in quantum physics and have potential applications in advanced computing, but they are sensitive to noise and difficult to control.* -
- The study introduces a new strategy that enhances the creation, preservation, and manipulation of large-scale GHZ entanglement, featuring experiments with digital quantum circuits achieving entanglement with up to 60 qubits.* -
- It utilizes discrete time crystals to increase the lifespan of GHZ states and demonstrates that superconducting processors can be an effective platform for exploring quantum entanglement and new applications.*
The ability to realize high-fidelity quantum communication is one of the many facets required to build generic quantum computing devices. In addition to quantum processing, sensing, and storage, transferring the resulting quantum states demands a careful design that finds no parallel in classical communication. Existing experimental demonstrations of quantum information transfer in solid-state quantum systems are largely confined to small chains with few qubits, often relying upon non-generic schemes.
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