A5016115632- Quantum Information and Cryptography
- Quantum Computing Algorithms and Architecture
- Quantum Mechanics and Applications
- Neural Networks and Reservoir Computing
- Quantum optics and atomic interactions
- Quantum and electron transport phenomena
- Cold Atom Physics and Bose-Einstein Condensates
- Ultrasonics and Acoustic Wave Propagation
- Quantum many-body systems
- Mechanical and Optical Resonators
- Advanced Thermodynamics and Statistical Mechanics
- Optical Network Technologies
- Spectroscopy and Quantum Chemical Studies
- Atomic and Subatomic Physics Research
- Advanced Fiber Laser Technologies
- Electrostatics and Colloid Interactions
- Photonic and Optical Devices
- Opinion Dynamics and Social Influence
- Acoustic Wave Resonator Technologies
- Electrical and Bioimpedance Tomography
- Advanced Optical Sensing Technologies
- Thermography and Photoacoustic Techniques
- Granular flow and fluidized beds
- Material Properties and Processing
- Flow Measurement and Analysis
Institute for Quantum Optics and Quantum Information Innsbruck
2015-2024
Austrian Academy of Sciences
2015-2024
Universität Innsbruck
2015-2024
Queensland University of Technology
2007-2011
Quantum (Australia)
2007-2011
The University of Queensland
2007-2011
University of Warwick
2005-2007
University of Toronto
2007
Deterministic quantum computation with one pure qubit (DQC1) is an efficient model of that uses highly mixed states. Unlike pure-state models, its power not derived from the generation a large amount entanglement. Instead it has been proposed other nonclassical correlations are responsible for computational speedup, and these can be captured by discord. In this Letter we implement DQC1 in all-optical architecture, experimentally observe generated correlations. We find no entanglement, but...
A series of trapped calcium ions was used to simulate the complex dynamics an interacting spin system.
Quantum-classical hybrid algorithms are a promising approach for near-term practical applications of quantum computers. A new experiment demonstrates how trapped-ion implementation one such algorithm solves chemistry problem.
Dynamical quantum phase transitions (DQPTs) extend the concept of and thus universality to non-equilibrium regime. In this letter, we investigate DQPTs in a string ions simulating interacting transverse-field Ising models. We observe dynamics induced by quench show for strings up 10 direct detection measuring quantity that becomes non-analytic time thermodynamic limit. Moreover, provide link between other relevant quantities such as magnetization, establish connection entanglement production.
Quantum walks have a host of applications, ranging from quantum computing to the simulation biological systems. We present an intrinsically stable, deterministic implementation discrete with single photons in space. The number optical elements required scales linearly steps. measure up 6 steps and explore quantum-to-classical transition by introducing tunable decoherence. Finally, we also investigate effect absorbing boundaries show that decoherence significantly affects probability absorption.
Shor's powerful quantum algorithm for factoring represents a major challenge in computation. Here, we implement compiled version photonic system. For the first time, demonstrate core processes, coherent control, and resultant entangled states required full-scale implementation. These are necessary steps on path towards scalable computing. Our results highlight that performance is not same as of underlying circuit stress importance developing techniques characterizing algorithms.
By weakly measuring the polarization of a photon between two strong measurements, we experimentally investigate correlation appearance anomalous values in quantum weak measurements and violation realism nonintrusiveness measurements. A quantitative formulation latter concept is expressed terms Leggett–Garg inequality for outcomes subsequent an individual system. We violate several measurement strengths. Furthermore, demonstrate that there one-to-one achieving strange violating inequality.
Entanglement is the key feature of many-body quantum systems, and development new tools to probe it in laboratory an outstanding challenge. Measuring entropy different partitions a system provides way its entanglement structure. Here, we present experimentally demonstrate protocol for measuring entropy, based on statistical correlations between randomized measurements. Our experiments, carried out with trapped-ion simulator, prove overall coherent character dynamics reveal growth parts -...
We generate and characterise entangled states of a register 20 individually controlled qubits, where each qubit is encoded into the electronic state trapped atomic ion. Entanglement generated amongst qubits during out-of-equilibrium dynamics an Ising-type Hamiltonian, engineered via laser fields. Since qubit-qubit interactions decay with distance, entanglement at early times predominantly between neighbouring groups qubits. these by designing applying witnesses for genuine multipartite...
The way in which energy is transported through an interacting system governs fundamental properties many areas of physics, chemistry, and biology. Remarkably, environmental noise can enhance the transport, effect known as environment-assisted quantum transport (ENAQT). In this paper, we study ENAQT a network coupled spins subject to engineered static disorder temporally varying dephasing noise. spin realized chain trapped atomic ions represented by transfer electronic excitation between...
We report on an elementary quantum network of two atomic ions separated by 230 m. The are trapped in different buildings and connected with 520(2) m optical fiber. At each node, the electronic state ion is entangled polarization a single cavity photon; subsequent to interference photons at beam splitter, photon detection heralds entanglement between ions. Fidelities up (88.0+2.2-4.7)% achieved respect maximally Bell state, success probability 4×10^{-5}. analyze routes improve these metrics,...
A quantum repeater node is presented based on trapped ions that act as single-photon emitters, memories, and an elementary processor. The node's ability to establish entanglement across two 25-km-long optical fibers independently, then swap efficiently extend it over both fibers, demonstrated. resultant established between telecom-wavelength photons at either end of the 50 km channel. Finally, system improvements allow for repeater-node chains stored 800 hertz rates are calculated, revealing...
We report on quantum simulations of relativistic scattering dynamics using trapped ions. The simulated state a particle is encoded in both the electronic and vibrational an ion, representing discrete continuous components wave functions. Multiple laser fields auxiliary ion simulate generated by Dirac equation presence potential. Measurement reconstruction packet enables frame-by-frame visualization processes. By precisely engineering range external potentials we are able to text book...
Quantum information carriers with higher dimension than the canonical qubit offer significant advantages. However, manipulating such systems is extremely difficult. We show how measurement induced non-linearities can be employed to dramatically extend range of possible transforms on biphotonic qutrits; three level quantum formed by polarisation two photons in same spatio-temporal mode. fully characterise biphoton-photon entanglement that underpins our technique, thereby realising first...
Although quantum computers promise significant advantages, the complexity of algorithms remains a major technological obstacle. We have developed and demonstrated an architecture-independent technique that simplifies adding control qubits to arbitrary operations-a requirement in many algorithms, simulations metrology. The technique, which is independent how operation done, does not require knowledge what is, largely separates problems implement laboratory add control. Here, we demonstrate...
A goal of the emerging field quantum control is to develop methods for technologies function robustly in presence noise. Central issues are fundamental limitations on available information about systems and disturbance they suffer process measurement. In context a simple scenario--the stabilization non-orthogonal states qubit against dephasing--we experimentally explore use weak measurements feedback control. We find that, despite intrinsic difficultly implementing them, allow us better...
Electromagnetically-induced-transparency (EIT) cooling is a ground-state technique for trapped particles. EIT offers broader range in frequency space compared to more established methods. In this work, we experimentally investigate strings of atomic ions. up 18 ions, demonstrate simultaneous all radial modes under 1 ms. This particularly important capability view emerging quantum simulation experiments with large numbers Our analysis the dynamics based on enabling single-shot measurements...
Recent advances in quantum simulators allow the use of systems trapped ions to create and simulate spin models with a controllable interaction range. Scientists report timely counterintuitive theoretical findings about temporal growth entanglement suddenly ``quenched'' chain based on ions.
Measurement-based quantum computation represents a powerful and flexible framework for information processing, based on the notion of entangled states as computational resources. The most prominent application is one-way computer, with cluster state its universal resource. Here we demonstrate principles measurement-based using deterministically generated states, in system trapped calcium ions. First implement set operations computing. Second family error correction codes show their improved...
A near optimum system for entangled photon collection and absorption in a single trapped ion is experimentally achieved: High-efficiency further demonstrated by the generation of multi-photon states with up to 15 photons.
A three-qubit quantum network node based on trapped atomic ions is presented. The ability to establish entanglement between each individual qubit in the and a separate photon that has traveled over 101-km-long optical fiber demonstrated. By sending those photons through close succession, remote rate achieved greater than when using only single node. Once extended more qubits, this multimode approach can be useful technique boost entanglement-distribution rates future long-distance networks...