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Transparent ferroelectric crystals with ultrahigh piezoelectricity 期刊论文
NATURE, 2020, 577 (7790) : 350-+
作者:  Qiu, Chaorui;  Wang, Bo;  Zhang, Nan;  Zhang, Shujun;  Liu, Jinfeng;  Walker, David;  Wang, Yu;  Tian, Hao;  Shrout, Thomas R.;  Xu, Zhuo;  Chen, Long-Qing;  Li, Fei
收藏  |  浏览/下载:50/0  |  提交时间:2020/07/03

Transparent piezoelectrics are highly desirable for numerous hybrid ultrasound-optical devices ranging from photoacoustic imaging transducers to transparent actuators for haptic applications(1-7). However, it is challenging to achieve high piezoelectricity and perfect transparency simultaneously because most high-performance piezoelectrics are ferroelectrics that contain high-density light-scattering domain walls. Here, through a combination of phase-field simulations and experiments, we demonstrate a relatively simple method of using an alternating-current electric field to engineer the domain structures of originally opaque rhombohedral Pb(Mg1/3Nb2/3)O-3-PbTiO3 (PMN-PT) crystals to simultaneously generate near-perfect transparency, an ultrahigh piezoelectric coefficient d(33) (greater than 2,100 picocoulombs per newton), an excellent electromechanical coupling factor k(33) (about 94 per cent) and a large electro-optical coefficient gamma(33) (approximately 220 picometres per volt), which is far beyond the performance of the commonly used transparent ferroelectric crystal LiNbO3. We find that increasing the domain size leads to a higher d(33) value for the [001]-oriented rhombohedral PMN-PT crystals, challenging the conventional wisdom that decreasing the domain size always results in higher piezoelectricity(8-10). This work presents a paradigm for achieving high transparency and piezoelectricity by ferroelectric domain engineering, and we expect the transparent ferroelectric crystals reported here to provide a route to a wide range of hybrid device applications, such as medical imaging, self-energy-harvesting touch screens and invisible robotic devices.


  
Coherent electrical control of a single high-spin nucleus in silicon 期刊论文
NATURE, 2020, 579 (7798) : 205-+
作者:  Dedoussi, Irene C.;  Eastham, Sebastian D.;  Monier, Erwan;  Barrett, Steven R. H.
收藏  |  浏览/下载:31/0  |  提交时间:2020/07/03

Nuclear spins are highly coherent quantum objects. In large ensembles, their control and detection via magnetic resonance is widely exploited, for example, in chemistry, medicine, materials science and mining. Nuclear spins also featured in early proposals for solid-state quantum computers(1) and demonstrations of quantum search(2) and factoring(3) algorithms. Scaling up such concepts requires controlling individual nuclei, which can be detected when coupled to an electron(4-6). However, the need to address the nuclei via oscillating magnetic fields complicates their integration in multi-spin nanoscale devices, because the field cannot be localized or screened. Control via electric fields would resolve this problem, but previous methods(7-9) relied on transducing electric signals into magnetic fields via the electron-nuclear hyperfine interaction, which severely affects nuclear coherence. Here we demonstrate the coherent quantum control of a single Sb-123 (spin-7/2) nucleus using localized electric fields produced within a silicon nanoelectronic device. The method exploits an idea proposed in 1961(10) but not previously realized experimentally with a single nucleus. Our results are quantitatively supported by a microscopic theoretical model that reveals how the purely electrical modulation of the nuclear electric quadrupole interaction results in coherent nuclear spin transitions that are uniquely addressable owing to lattice strain. The spin dephasing time, 0.1 seconds, is orders of magnitude longer than those obtained by methods that require a coupled electron spin to achieve electrical driving. These results show that high-spin quadrupolar nuclei could be deployed as chaotic models, strain sensors and hybrid spin-mechanical quantum systems using all-electrical controls. Integrating electrically controllable nuclei with quantum dots(11,12) could pave the way to scalable, nuclear- and electron-spin-based quantum computers in silicon that operate without the need for oscillating magnetic fields.


  
On the Road to Transportation Efficiency (Video) 科技报告
来源:US Department of Energy (DOE). 出版年: 2014
作者:  [null]
收藏  |  浏览/下载:14/0  |  提交时间:2019/04/05
VEHICLES  ELECTRIC AND HYBRID ELECTRIC  HEAVY DUTY  LIGHT DUTY  ELECTRIFIED ROADWAYS  E-ROADWAYS  
Plug-In Electric Vehicle Handbook for Fleet Managers (Brochure) 科技报告
来源:US Department of Energy (DOE). 出版年: 2012
作者:  [null]
收藏  |  浏览/下载:24/0  |  提交时间:2019/04/05
CLEAN CITIES  CHARGING  DRIVING  ELECTRIC VEHICLE  EV  FLEET  MAINTENANCE  PEV  PHEV  PLUG-IN ELECTRIC VEHICLE  PLUG-IN HYBRID ELECTRIC VEHICLE  Hybrid Electric Vehicles  Energy Efficiency and Renewable Energy  
Interim Project Results: United Parcel Service's Second-Generation Hybrid-Electric Delivery Vans (Fact Sheet) 科技报告
来源:US Department of Energy (DOE). 出版年: 2012
作者:  [null]
收藏  |  浏览/下载:25/0  |  提交时间:2019/04/05
NREL FLEET TEST AND EVALUATION TEAM  RENEWABLE FUELS AND LUBRICANTS LABORATORY  REFUEL LABORATORY  EMISSIONS TESTING  FUEL ECONOMY TESTING  UNITED PARCEL SERVICE SECOND-GENERATION HYBRID-ELECTRIC DELIVERY VANS  ENGINE OFF AT IDLE  EATON CORP. PARALLEL HYB  
Clean Cities Now: Vol. 15, No. 2, October 2011 (Brochure) (Revised) 科技报告
来源:US Department of Energy (DOE). 出版年: 2011
作者:  Olama, Mohammed M [ORNL];  Allgood, Glenn O [ORNL];  Kuruganti, Phani Teja [ORNL];  Sukumar, Sreenivas R [ORNL];  Woodworth, Ken [ORNL];  Lake, Joe E [ORNL]
收藏  |  浏览/下载:17/0  |  提交时间:2019/04/05
CLEAN CITIES NOW  CLEAN CITIES  ELECTRIC VEHICLES  NATURAL GAS  ETHANOL  IDLE REDUCTION  HYBRID ELECTRIC VEHICLES  BIODIESEL  INDIANAPOLIS  Energy Efficiency and Renewable Energy  Market Transformation  
What is Clean Cities? October 2011 (Brochure) 科技报告
来源:US Department of Energy (DOE). 出版年: 2011
作者:  Zoubul, G.;  Cahoon, M.;  Kolb, R.
收藏  |  浏览/下载:19/0  |  提交时间:2019/04/05
CLEAN CITIES  COALITIONS  COORDINATORS  ALTERNATIVE FUELS  ALTERNATIVE FUEL VEHICLES  AFV  IDLE REDUCTION  FUEL ECONOMY  HYBRID ELECTRIC VEHICLE  Market Transformation  Energy Efficiency and Renewable Energy