A5041357247- Quantum and electron transport phenomena
- Molecular Junctions and Nanostructures
- Graphene research and applications
- Semiconductor materials and devices
- Advancements in Semiconductor Devices and Circuit Design
- Quantum Computing Algorithms and Architecture
- Physics of Superconductivity and Magnetism
- Magnetism in coordination complexes
- Quantum Information and Cryptography
- Atomic and Subatomic Physics Research
- Quantum optics and atomic interactions
- Semiconductor Quantum Structures and Devices
- Surface and Thin Film Phenomena
- Mechanical and Optical Resonators
- Quantum Dots Synthesis And Properties
- Molecular spectroscopy and chirality
- Topological Materials and Phenomena
- Advanced NMR Techniques and Applications
- Seismology and Earthquake Studies
- Analog and Mixed-Signal Circuit Design
- Laser-Matter Interactions and Applications
- Magnetic properties of thin films
- Magnetic Field Sensors Techniques
- Electrochemical Analysis and Applications
- Acoustic Wave Resonator Technologies
Institut Néel
2012-2025
Université Grenoble Alpes
2015-2023
Centre National de la Recherche Scientifique
2009-2023
Institut polytechnique de Grenoble
2019-2022
Karlsruhe Institute of Technology
2019
Institut Universitaire de France
2014-2018
Université Joseph Fourier
2001-2012
Delft University of Technology
2004-2006
Recent advances in addressing isolated nuclear spins have opened up a path toward using nuclear-spin-based quantum bits. Local magnetic fields are normally used to coherently manipulate the state of spin; however, electrical manipulation would allow for fast switching and spatially confined spin control. Here, we propose demonstrate coherent single electric only. Because there is no direct coupling between field, make use hyperfine Stark effect as field transducer at atomic level. This...
Quantum algorithms use the principles of quantum mechanics, such as, for example, superposition, in order to solve particular problems outperforming standard computation. They are developed cryptography, searching, optimization, simulation, and solving large systems linear equations. Here, we implement Grover's algorithm, proposed find an element unsorted list, using a single nuclear 3/2 spin carried by Tb ion sitting molecular magnet transistor. The coherent manipulation this multilevel...
We present the experimental realization of a quantum dot (QD) operating as high-frequency noise detector. Current fluctuations produced in nearby point contact (QPC) ionize QD and induce transport through excited states. The resulting transient current represents our detector signal. investigate its dependence on QPC transmission voltage bias. observe explain threshold feature saturation This theoretical study is relevant understanding backaction used charge
An on-chip detection scheme for high frequency signals is used to detect noise generated by a quantum dot formed in single wall carbon nanotube. The based on photon assisted tunneling superconductor-insulator-superconductor junction. Measurements of shot over full Coulomb diamond are reported with excited states and inelastic cotunneling clearly resolved. Super-Poissonian detected the case cotunneling.
We present the first quantitative experimental evidence for underscreened Kondo effect, an uncomplete compensation of a quantized magnetic moment by conduction electrons, as originally proposed Nozieres and Blandin. The device consists even charge spin S = 1 molecular quantum dot, obtained electromigration C60 molecules into gold nanogaps operated in dilution fridge. persistence logarithmic singularities low temperature conductance is demonstrated comparison to fully screened configuration...
We present the electrical readout of time trajectories obtained from an isolated nuclear spin. The device, a ${\mathrm{TbPc}}_{2}$ single-molecule magnet spin transistor, detects four different states ${\mathrm{Tb}}^{3+}$ ion with fidelities better than 69%, allowing us to measure individual relaxation times (${T}_{1}$) several tens seconds. A good agreement quantum Monte Carlo simulations suggests that are limited by current tunneling through which opens up possibility tune ${T}_{1}$...
The recent development of arrays quantum dots in semiconductor nanostructures highlights the progress devices toward large scale. However, how to realize such on a scalable platform as silicon is still an open question. One main challenge resides detection charges within array. It prerequisite functionality initialize desired charge state and readout spins through spin-to-charge conversion mechanisms. In this paper, we use two methods based either single-lead detector, or reprogrammable...
We have observed coherent oscillations in a multilevel quantum system, formed by current-biased dc SQUID. These been induced applying resonant microwave pulses of flux. Quantum measurement is performed nanosecond flux pulse that projects the final state onto one two different voltage states SQUID, which can be read out. The number involved increases with increasing power. dependence oscillation frequency on power deviates strongly from linear regime expected for two-level system and very...
We present an original way of continuously reading-out the state a single electronic spin. Our detection scheme is based on exchange interaction between spin and nearby read-out quantum dot. The coupling two systems results in spin-dependent conductance through dot establishes all electrical nondestructive detection. With variations up to 4% fidelities greater than 99.5%, this method represents alternative for which spin-to-charge conversion cannot be implemented. Using semiclassical...
Several technological issues have to be faced realize devices working at the single molecule level. One of main challenges consists defining methods fabricate electrodes make contact with molecules. Here, we report realization novel spintronic made a TbPc2 embedded between two nanometer-separated graphene electrodes, obtained by feedback-controlled electroburning. We demonstrate that this approach allows realisation low temperature. With these, were able characterize magnetic exchange...
Abstract Quantum technologies are expected to introduce revolutionary changes in information processing the near future. Nowadays, one of main challenges is be able handle a large number quantum bits (qubits), while preserving their properties. Beyond usual two-level encoding capacity qubits, multi-level systems promising way extend and increase amount that can stored same objects. Recent work (Kues et al. 2017), has shown possibility use devices based on photonic integrated circuits...
Pauli-spin-blockade (PSB) measurements have so far achieved the highest fidelity of spin readout in semiconductor quantum dots, overcoming 99% threshold. Moreover, contrast to energy-selective readout, PSB is less error prone thermal energy, an important feature for large-scale architectures that could be operated at temperatures above a few hundreds millikelvins. In this work, we use rf reflectometry on single-lead dot perform charge sensing and probe state double 0.5 K. At relatively...
We review here some universal aspects of the physics two-electron molecular transistors in absence strong spin–orbit effects. Several recent quantum dot experiments have shown that an electrostatic backgate could be used to control energy dispersion magnetic levels. discuss how generally asymmetric coupling metallic contacts two different orbitals can indeed lead a gate-tunable Hund's rule presence singlet and triplet states dot. For gate voltages such constitutes (non-magnetic) ground...
We present an experimental and theoretical study of a magnetic single-molecule transistor based on N@C60 connected to gold electrodes. Particular attention is paid the regime intermediate molecule-lead coupling, where cotunneling effects manifest themselves in Coulomb-blockade regime. The results for differential conductance as function bias, gate voltage, external field are agreement with our analysis tunneling rates provide evidence signatures single-N@C60 devices arising from...
The escape probability out of the superconducting state a hysteretic dc SQUID has been measured at different values applied magnetic flux. At low temperatures, current and width distribution are temperature independent but they depend on Experimental results do not fit usual one-dimensional macroscopic quantum tunneling (MQT) law perfectly accounted for by two-dimensional MQT behavior as we propose here. Near zero flux, our data confirms recent observation in [S. Li et al., Phys. Rev. Lett....
A new method based on the electrochemical oxidation of thiols was used to easily generate multilayer assemblies coordination complexes a gold surface. For this purpose, two bearing anchoring groups for surface attachment have been prepared: [Ru(tpySH)(2)](2+) (1) and [Fe(tpySH)(2)](2+) (2) (tpySH = 4'-(2-(p-phenoxy)ethanethiol)-2,2':6',2″-terpyridine). Cyclic voltammetry 1 in CH(3)CN exhibits successive processes. The first is irreversible attributed thiol substituents, whereas second...
We monitor the Landau-Zener dynamics of a single-ion magnet inserted into spin-transistor geometry. For increasing field-sweep rates, spin reversal probability shows deviations from that closed system. In low-conductance limit, such are shown to result dephasing process. particular, observed behaviors successfully simulated by means an adiabatic master equation, with time averaged (Lindblad) operators. The average is tentatively interpreted in terms finite resolution continuous measurement.
We propose a single shot quantum measurement to determine the state of Josephson charge bit (qubit). The qubit is Cooper pair box (CPB) and measuring device two junction superconducting interference (dc-SQUID). This coupled system exhibits close analogy with Rydberg atom in high Q cavity, except that present we benefit from additional feature escape supercurrent by macroscopic tunneling, which provides final read-out. test feasibility our idea against realistic experimental circuit...
Graphene-based electrodes are very promising for molecular electronics and spintronics. Here we report a systematic characterization of the electroburning (EB) process, leading to formation nanometer-spaced gaps, on different types few-layer graphene (namely mechanically exfoliated SiO2, epitaxially grown C-face SiC turbostratic discs deposited SiO2) under air vacuum conditions. The EB process is found depend both type ambient For graphene, performing leads higher yield nanometer-gap than...
Qudits, with their state space of dimension d > 2, open fascinating experimental prospects. The quantum properties states provide new potentialities for information, contextuality, expressions geometric phases, facets entanglement and many other foundational aspects the world, which are unapproachable qubits. We here experimentally investigate dynamics a qudit (d = 4) that consists single 3/2 nuclear spin embedded in molecular magnet transistor geometry, coherently driven by microwave...