scholarly journals Quantum sensors for microscopic tunneling systems

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Alexander Bilmes ◽  
Serhii Volosheniuk ◽  
Jan David Brehm ◽  
Alexey V. Ustinov ◽  
Jürgen Lisenfeld

AbstractThe anomalous low-temperature properties of glasses arise from intrinsic excitable entities, so-called tunneling Two-Level-Systems (TLS), whose microscopic nature has been baffling solid-state physicists for decades. TLS have become particularly important for micro-fabricated quantum devices such as superconducting qubits, where they are a major source of decoherence. Here, we present a method to characterize individual TLS in virtually arbitrary materials deposited as thin films. The material is used as the dielectric in a capacitor that shunts the Josephson junction of a superconducting qubit. In such a hybrid quantum system the qubit serves as an interface to detect and control individual TLS. We demonstrate spectroscopic measurements of TLS resonances, evaluate their coupling to applied strain and DC-electric fields, and find evidence of strong interaction between coherent TLS in the sample material. Our approach opens avenues for quantum material spectroscopy to investigate the structure of tunneling defects and to develop low-loss dielectrics that are urgently required for the advancement of superconducting quantum computers.

2021 ◽  
Author(s):  
Abhinandan Antony ◽  
Martin Gustafsson ◽  
Guilhem Ribeill ◽  
Matthew Ware ◽  
Anjaly Rajendran ◽  
...  

Abstract Quantum computers can potentially achieve an exponential speedup versus classical computers on certain computational tasks, recently demonstrated in systems of superconducting qubits. However, the capacitor electrodes that comprise these qubits must be large in order to avoid lossy dielectrics. This tactic hinders scaling by increasing parasitic coupling among circuit components, degrading individual qubit addressability, and limiting the spatial density of qubits. Here, we take advantage of the unique properties of van der Waals (vdW) materials to reduce the qubit area by $>1000$ times while preserving the required capacitance without increasing substantial loss. Our qubits combine conventional aluminum-based Josephson junctions with parallel-plate capacitors composed of crystalline layers of superconducting niobium diselenide and insulating hexagonal-boron nitride. We measure a vdW transmon $T_1$ relaxation time of 1.06 $\mu$s, which demonstrates a path to achieve high-qubit-density quantum processors with long coherence times, and the broad utility of layered heterostructures in low-loss, high-coherence quantum devices.


Author(s):  
R. R. Dils ◽  
P. S. Follansbee

Electric fields have been applied across oxides growing on a high temperature alloy and control of the oxidation of the material has been demonstrated. At present, three-fold increases in the oxidation rate have been measured in accelerating fields and the oxidation process has been completely stopped in a retarding field.The experiments have been conducted with an iron-base alloy, Pe 25Cr 5A1 0.1Y, although, in principle, any alloy capable of forming an adherent aluminum oxide layer during oxidation can be used. A specimen is polished and oxidized to produce a thin, uniform insulating layer on one surface. Three platinum electrodes are sputtered on the oxide surface and the specimen is reoxidized.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Israel F. Araujo ◽  
Daniel K. Park ◽  
Francesco Petruccione ◽  
Adenilton J. da Silva

AbstractAdvantages in several fields of research and industry are expected with the rise of quantum computers. However, the computational cost to load classical data in quantum computers can impose restrictions on possible quantum speedups. Known algorithms to create arbitrary quantum states require quantum circuits with depth O(N) to load an N-dimensional vector. Here, we show that it is possible to load an N-dimensional vector with exponential time advantage using a quantum circuit with polylogarithmic depth and entangled information in ancillary qubits. Results show that we can efficiently load data in quantum devices using a divide-and-conquer strategy to exchange computational time for space. We demonstrate a proof of concept on a real quantum device and present two applications for quantum machine learning. We expect that this new loading strategy allows the quantum speedup of tasks that require to load a significant volume of information to quantum devices.


2020 ◽  
Vol 9 (01) ◽  
pp. 24919-24920
Author(s):  
Viplove Divyasheesh ◽  
Rakesh Jain

Quantum computers consist of a quantum processor – sets of quantum bits or qubits operating at an extremely low temperature – and a classical electronic controller to read out and control the processor. The machines utilize the unusual properties of matter at extremely small scales – the fact that a qubit, can represent “1” and “0” at the same time, a phenomenon known as superposition. (In traditional digital computing, transistors in silicon chips can exist in one of two states represented in binary by a 1 or 0 not both). Under the right conditions, computations carried out with qubits are equivalent to numerous classical computations performed in parallel, thus greatly enhancing computing power compared to today’s powerful supercomputers and the ability to solve complex problems without the sort of experiments necessary to generate quantum phenomena. this technology is unstable and needs to be stored in a cool environment for faster and more secure operation.In this paper, we discuss the possibility of integrating quantum computers with electronics at deep cryogenic temperatures.  


2011 ◽  
Vol 09 (06) ◽  
pp. 1459-1497 ◽  
Author(s):  
ABDULLAH M. ILIYASU ◽  
PHUC Q. LE ◽  
FANGYAN DONG ◽  
KAORU HIROTA

Adopting a generalization of the DiVincenzo criteria for the physical realization of quantum devices, a standalone component each, is proposed to prepare, manipulate, and measure the various content required to represent and produce movies on quantum computers. The quantum CD encodes, prepares, and initializes the broad content or key frames conveying the movie script. The quantum player uses the simple motion operations to manipulate the contents of the key frames in order to interpolate the missing viewing frames required to effectively depict the shots and scenes of the movie. The movie reader combines the projective measurement technique and the ancilla-driven quantum computation to retrieve the classical movie sequence comprising of both the key and viewing frames for each shot. At appropriate frame transition rates, this sequence creates the impression of continuity in order to depict the various movements and actions in the movie. Two well-thought-out examples demonstrate the feasibility of the proposed framework. Concatenated, these components together facilitate the proposed framework for quantum movie representation and production, thus, opening the door towards manipulating quantum circuits aimed at applications for information representation and processing.


ChemPhysChem ◽  
2020 ◽  
Vol 21 (15) ◽  
pp. 1737-1737
Author(s):  
Rinat Meir ◽  
Hui Chen ◽  
Wenzhen Lai ◽  
Sason Shaik

2020 ◽  
Author(s):  
авторов Коллектив

Настоящий том посвящен актуальным проблемам квантовых технологий и микроэлектроники. Рассмотрены различные численные и аналитические подходы к моделированию и контролю элементной базы квантовых компьютеров и симуляторов с учетом декогерентизации и квантовых шумов. Представлены современные методы, направленные на инжиниринг различных квантовых состояний, а также их адекватный, полный и точный контроль. Представлены разработки, обеспечивающие существенное улучшение процедур томографии квантовых состояний и операций с учетом несовершенства технологий и измерений. Кроме того, рассмотрены некоторые вопросы, связанные с разработкой и моделированием приборов микроэлектроники и наноэлектроники. Для широкого круга специалистов в области квантовых информационных технологий, микро- и наноэлектроники, а также студентов и аспирантов, обучающихся по соответствующим специальностям. This volume is devoted to topical problems of quantum technologies and microelectronics. Various numerical and analytical approaches to modeling and control of the element base of quantum computers and simulators, taking into account decoherence and quantum noise, are considered. The modern methods aimed at engineering various quantum states, as well as their adequate, complete and accurate control are presented. Developments are presented that provide a significant improvement in the procedures for tomography of quantum states and operations, taking into account the imperfection of technologies and measurements. In addition, some issues related to the development and modeling of microelectronic and nanoelectronic devices are considered. Intended for a wide range of specialists in the field of quantum information technologies, as well as in the field of micro- and nanoelectronics; it can also be recommended to undergraduate and graduate students of relevant specialties.вЃ


2007 ◽  
Vol 12 (5) ◽  
pp. 267-276 ◽  
Author(s):  
Dietrich Dehlinger ◽  
Benjamin Sullivan ◽  
Sadik Esener ◽  
Dalibor Hodko ◽  
Paul Swanson ◽  
...  

A fully automated electronic microarray control system (Nanochip 400 System) was used to carry out a combinatorial process to determine optimal conditions for fabricating higher order three-dimensional nanoparticle structures. Structures with up to 40 layers of bioderivatized nanoparticles were fabricated on a 400-test site CMOS microarray using the automated Nanochip 400 System. Reconfigurable electric fields produced on the surface of the CMOS microarray device actively transport, concentrate, and promote binding of 40 nm biotin- and streptavidin-derivatized nanoparticles to selected test sites on the microarray surface. The overall fabrication process including nanoparticle reagent delivery to the microarray device, electronic control of the CMOS microarray and the optical/fluorescent detection, and monitoring of nanoparticle layering are entirely controlled by the Nanochip 400 System. The automated nanoparticle layering process takes about 2 minutes per layer, with 10–20 seconds required for the electronic addressing and binding of nanoparticles, and roughly 60 seconds for washing. The addressing and building process is monitored by changes in fluorescence intensity as each nanoparticle layer is deposited. The final multilayered 3D structures are about 2 μm in thickness and 55 μm in diameter. Multilayer nanoparticle structures and control sites on the microarray were verified by SEM analysis.


2012 ◽  
Vol 1403 ◽  
Author(s):  
Shan Wu ◽  
Minren Lin ◽  
David S-G. Lu ◽  
Lei Zhu ◽  
Q. M. Zhang

ABSTRACTDielectric polymers with high energy density with low loss at high electric fields are highly desired for many energy storage and regulation applications. A polar-fluoropolymer blend consisting of a high energy density polar-fluoropolymer of poly(vinylidene fluoride-chlorotrifluoroethylene) (P(VDF-CTFE)) with a low dielectric loss polymer of poly(ethylene-chlorotrifluoroethylene) (ECTFE) was developed and investigated. We show that the two polymers are partially miscible which leads to blends with high energy density and low loss. Moreover, by introducing crosslinking to further tailor the nano-structures of the blends a markedly reduction of losses in the blend films at high field can be achieved. The crosslinked blend films show a dielectric constant of 7 with a dielectric loss of 1% at low field. Furthermore, the blends maintain a high energy density and low loss (∼3%) at high electric fields (> 250 MV/m).


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