Dynamical decoupling in interacting systems: applications to signal-enhanced hyperpolarized readout
A. Ajoy, R. Nirodi, A. Sarkar, P. Reshetikhin, E. Druga, A. Akkiraju, M. McAllister, G. Maineri, S. Le, A. Lin, A. M. Souza, C. A. Meriles, B. Gilbert, D. Suter… 展开作者
A. Ajoy, R. Nirodi, A. Sarkar, P. Reshetikhin, E. Druga, A. Akkiraju, M. McAllister, G. Maineri, S. Le, A. Lin, A. M. Souza, C. A. Meriles, B. Gilbert, D. Suter, J. A. Reimer, A. Pines
备注：
6+6 pages. Originally submitted to peer-review on 04 May 2020
Methods that preserve coherence broadly impact all quantum information processing and metrology applications. Dynamical decoupling methods accomplish this by protecting qubits in noisy environments but are typically constrained to the limit where the qubits themselves are non-interacting. Here we consider the alternate regime wherein the inter-qubit couplings are of the same order as dephasing interactions with the environment. We propose and demonstrate a multi-pulse protocol that protects transverse spin states by suitably Hamiltonian engineering the inter-spin coupling while simultaneously suppressing dephasing noise on the qubits. We benchmark the method on 13C nuclear spin qubits in diamond, dipolar coupled to each other and embedded in a noisy electronic spin bath, and hyperpolarized via optically pumped NV centers. We observe effective state lifetimes of 13C nuclei $T_2^{\prime}\approx$2.5s at room temperature, an extension of over 4700-fold over the conventional $T_2^{\ast}$ free induction decay. The spins are continuously interrogated during the applied quantum control, resulting in 13C NMR line narrowing and an $>$500-fold boost in SNR due to the lifetime extension. Together with hyperpolarization spin interrogation is accelerated by $>10^{11}$ over conventional 7T NMR. This work suggests strategies for the dynamical decoupling of coupled qubit systems with applications in a variety of experimental platforms.
We report the observation of long-lived Floquet prethermal states in a bulk solid composed of dipolar-coupled $^{13}$C nuclei in diamond at room temperature. For precessing nuclear spins prepared in an initial transverse state, we demonstrate pulsed spin-lock Floquet control that prevents their decay over multiple-minute long periods. We observe Floquet prethermal lifetimes $T_2'\approx$90.9s, extended >60,000-fold over the nuclear free induction decay times. The spins themselves are continuously interrogated for $\sim$10min, corresponding to the application of $\approx$5.8M control pulses. Th…
We demonstrate a method to quantify and manipulate nuclear spin decoherence mechanisms that are active in zero to ultralow magnetic fields. These include: (i) non-adiabatic switching of spin quantization axis, due to residual background fields; (ii) scalar pathways due to through-bond couplings between $^1$H and heteronuclear spin species, such as $^2$H used partially as an isotopic substitute for $^1$H. Under conditions of free evolution, scalar relaxation due to $^2$H can significantly limit nuclear spin polarization lifetimes and thus the scope of magnetic resonance procedures near zero fie…
Coherence time is an essential parameter for quantum sensing, quantum information, and quantum computation. In this work, we demonstrate electron spin coherence times as long as 0.1 s for an ensemble of rubidium atoms trapped in a solid parahydrogen matrix. We explore the underlying physics limiting the coherence time. The properties of these matrix isolated atoms are very promising for future applications, including quantum sensing of nuclear spins. If combined with efficient single-atom readout, this would enable NMR and magnetic resonance imaging of single molecules cotrapped with alkali-me…
An outstanding hurdle for defect spin qubits in silicon carbide (SiC) is single-shot readout - a deterministic measurement of the quantum state. Here, we demonstrate single-shot readout of single defects in SiC via spin-to-charge conversion, whereby the defect's spin state is mapped onto a long-lived charge state. With this technique, we achieve over 80% readout fidelity without pre- or post-selection, resulting in a high signal-to-noise ratio (SNR) that enables us to measure long spin coherence times. Combined with pulsed dynamical decoupling sequences in an isotopically purified host materia…
Optically detected nuclear magnetic resonance of carbon-13 in bulk diamond
Center for High Technology Materials, University of New Mexico（新墨西哥大学高等技术材料中心）；Department of Physics and Astronomy, University of New Mexico（新墨西哥大学物理与天文学系）；Department of Physics and Astronomy, Dartmouth College（达特茅斯学院物理与天文学系）；DEVCOM Army Research Laboratory（美国陆军研究与发展司令部陆军研究实验室）
The realization of an efficient quantum optical interface for multi-qubit systems is an outstanding challenge in science and engineering. Using two atoms in individually-controlled optical tweezers coupled to a nanofabricated photonic crystal cavity, we demonstrate entanglement generation, fast non-destructive readout, and full quantum control of atomic qubits. The entangled state is verified in free space after being transported away from the cavity by encoding the qubits into long-lived states and using dynamical decoupling. Our approach bridges quantum operations at an optical link and in f…
Parahydrogen Cooling of Nuclear Spin Chains at Hypogeomagnetic Fields
International Tomography Center, SB RAS（俄罗斯科学院西伯利亚分院国际成像中心）；Novosibirsk State University（新西伯利亚国立大学）；Chimie Physique et Chimie du Vivant (CPCV, UMR 8228), Département de Chimie, École Normale Supérieure, PSL University, Sorbonne Université（巴黎高等师范学院化学系物理与生命化学实验室（CPCV，UMR 8228），PSL大学，索邦大学）；Johannes Gutenberg University, Institute of Physics（约翰内斯·古腾堡大学物理研究所）；Helmholtz Institute Mainz（美因茨亥姆霍兹研究所）；GSI Helmholtzzentrum für Schwerionenforschung GmbH（德国重离子研究中心亥姆霍兹有限公司）；Department of Chemistry, University of Miami（迈阿密大学化学系）；Department of Physics, University of Miami（迈阿密大学物理系）；Frost Institute for Chemistry and Molecular Science（弗罗斯特化学与分子科学研究所）
One of the most challenging problems for the realization of a scalable quantum computer is to design a physical device that keeps the error rate for each quantum processing operation low. These errors can originate from the accuracy of quantum manipulation, such as the sweeping of a gate voltage in solid state qubits or the duration of a laser pulse in optical schemes. Errors also result from decoherence, which is often regarded as more crucial in the sense that it is inherent to the quantum system, being fundamentally a consequence of the coupling to the external environment. Grouping small c…
Coherence Protection for Mobile Spin Qubits in Silicon
Leiden University（莱顿大学）；Delft University of Technology（代尔夫特理工大学）；QuTech；Kavli Institute of Nanoscience, Delft University of Technology（代尔夫特理工大学卡弗里纳米科学研究所）；Netherlands Organization for Applied Scientific Research (TNO)（荷兰应用科学研究组织）
Demonstrating Noise-adapted Quantum Error Correction With Break-Even Performance
Indian Institute of Technology Madras（印度理工学院马德拉斯分校）；Center for Quantum Information, Communication and Computing, IIT Madras（印度理工学院马德拉斯量子信息、通信与计算中心）；University College London（伦敦大学学院）
