I.SUPPLEMENTARY NOTE 1:THEORETICAL MATERIALS.The quantum speed limit(QSL)is essential for quantum computing and quantum communication,referring to the minimum time required for a quantum system to evolve from one stat...I.SUPPLEMENTARY NOTE 1:THEORETICAL MATERIALS.The quantum speed limit(QSL)is essential for quantum computing and quantum communication,referring to the minimum time required for a quantum system to evolve from one state to another.Two well-known forms of the QSL are the Mandelstam-Tamm(MT)relation TqsL≥πh/2△E[S1]and the Margolus-Levitin(ML)relation TqsL≥πh/2(E)[S2]where Tqst is denoted as the QSL time,h is the reduced Planck's constant,△E is the energy uncertainty(standard deviation)of the system,and(E)is the average energy of the system above its ground state.Both of relations provide a lower bound on the evolution time.展开更多
Adiabatic time-optimal quantum controls are extensively used in quantum technologies to break the constraints imposed by short coherence times.However,practically it is crucial to consider the trade-off between the qu...Adiabatic time-optimal quantum controls are extensively used in quantum technologies to break the constraints imposed by short coherence times.However,practically it is crucial to consider the trade-off between the quantum evolution speed and instantaneous energy cost of process because of the constraints in the available control Hamiltonian.Here,we experimentally show that using a transmon qubit that,even in the presence of vanishing energy gaps,it is possible to reach a highly time-optimal adiabatic quantum driving at low energy cost in the whole evolution process.This validates the recently derived general solution of the quantum Zermelo navigation problem,paving the way for energy-efficient quantum control which is usually overlooked in conventional speed-up schemes,including the well-known counter-diabatic driving.By designing the control Hamiltonian based on the quantum speed limit bound quantified by the changing rate of phase in the interaction picture,we reveal the relationship between the quantum speed limit and instantaneous energy cost.Consequently,we demonstrate fast and high-fidelity quantum adiabatic processes by employing energy-efficient driving strengths,indicating a promising strategy for expanding the applications of time-optimal quantum controls in superconducting quantum circuits.展开更多
用一步水热法合成多孔的爆米花形状的由还原石墨烯包裹的FeS纳米颗粒,该复合颗粒作为钠离子电池阳极使用.多孔结构因为大的表面积有助于该复合物展现出优越的循环稳定性和速率性能.在电流密度为100 mA g-1时,100次循环之后该复合物依然...用一步水热法合成多孔的爆米花形状的由还原石墨烯包裹的FeS纳米颗粒,该复合颗粒作为钠离子电池阳极使用.多孔结构因为大的表面积有助于该复合物展现出优越的循环稳定性和速率性能.在电流密度为100 mA g-1时,100次循环之后该复合物依然保持可逆比容量为552 mA h g-1;在电流密度为5000 mA g-1时,表现出比容量为307 mA h g-1.此外,Na, S和Fe的相图分析揭露了Na和FeS在充放电过程中的氧化还原机制.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.92165206 and 11974330)the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0301603)the Fundamental Research Funds for the Central Universities。
文摘I.SUPPLEMENTARY NOTE 1:THEORETICAL MATERIALS.The quantum speed limit(QSL)is essential for quantum computing and quantum communication,referring to the minimum time required for a quantum system to evolve from one state to another.Two well-known forms of the QSL are the Mandelstam-Tamm(MT)relation TqsL≥πh/2△E[S1]and the Margolus-Levitin(ML)relation TqsL≥πh/2(E)[S2]where Tqst is denoted as the QSL time,h is the reduced Planck's constant,△E is the energy uncertainty(standard deviation)of the system,and(E)is the average energy of the system above its ground state.Both of relations provide a lower bound on the evolution time.
基金supported by the National Natural Science Foundation of China(Grant Nos.U21A20436 and 12074179)the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0301702)+2 种基金the Natural Science Foundation of Jiangsu Province(Grant Nos.BE2021015-1 and BK20232002)the Jiangsu Funding Program for Excellent Postdoctoral Talent(Grant Nos.20220ZB16 and 2023ZB562)the Natural Science Foundation of Shandong Province(Grant No.ZR2023LZH002)。
文摘Adiabatic time-optimal quantum controls are extensively used in quantum technologies to break the constraints imposed by short coherence times.However,practically it is crucial to consider the trade-off between the quantum evolution speed and instantaneous energy cost of process because of the constraints in the available control Hamiltonian.Here,we experimentally show that using a transmon qubit that,even in the presence of vanishing energy gaps,it is possible to reach a highly time-optimal adiabatic quantum driving at low energy cost in the whole evolution process.This validates the recently derived general solution of the quantum Zermelo navigation problem,paving the way for energy-efficient quantum control which is usually overlooked in conventional speed-up schemes,including the well-known counter-diabatic driving.By designing the control Hamiltonian based on the quantum speed limit bound quantified by the changing rate of phase in the interaction picture,we reveal the relationship between the quantum speed limit and instantaneous energy cost.Consequently,we demonstrate fast and high-fidelity quantum adiabatic processes by employing energy-efficient driving strengths,indicating a promising strategy for expanding the applications of time-optimal quantum controls in superconducting quantum circuits.
文摘用一步水热法合成多孔的爆米花形状的由还原石墨烯包裹的FeS纳米颗粒,该复合颗粒作为钠离子电池阳极使用.多孔结构因为大的表面积有助于该复合物展现出优越的循环稳定性和速率性能.在电流密度为100 mA g-1时,100次循环之后该复合物依然保持可逆比容量为552 mA h g-1;在电流密度为5000 mA g-1时,表现出比容量为307 mA h g-1.此外,Na, S和Fe的相图分析揭露了Na和FeS在充放电过程中的氧化还原机制.
