Related papers: High Speed, High Fidelity Detection of an Atomic H…
Coherent storage of quantum information is crucial to many quantum technologies. Long coherence times have been demonstrated in trapped-ion qubits, typically using the hyperfine levels within the ground state of a single ion. However,…
The stable operation of quantum computers will rely on error-correction, in which single quantum bits of information are stored redundantly in the Hilbert space of a larger system. Such encoded qubits are commonly based on arrays of many…
We present a comprehensive theoretical investigation of hyperfine-resolved excitation and detection of the low-energy isomeric state of $^{229}$Th in trapped $^{229}\mathrm{Th}^{3+}$ ions. Using a quantum master equation approach, we…
Population leakage outside the qubit subspace presents a particularly harmful source of error that cannot be handled by standard error correction methods. Using a trapped $^{171}$Yb$+$ ion, we demonstrate an optical pumping scheme to…
Trapped atoms and ions are among the best controlled quantum systems which find widespread applications in quantum information, sensing and metrology. For molecules, however, a similar degree of control is currently lacking owing to their…
We describe an atom trapping mechanism based upon differential optical pumping between metastable hyperfine states by partially-displaced laser beams in the absence of a magnetic field. With realistic laser powers, trap spring constants…
A single Yb atom is loaded into a high-finesse optical cavity with a moving lattice, and its nuclear spin state is manipulated using a nuclear magnetic resonance technique. A highly reliable quantum state control with fidelity and purity…
We study ultracold collisions of ions with neutral atoms in traps. Recently, ultracold atom-ion systems are becoming available in experimental setups, where their quantum states can be coherently controlled. This allows for an…
Reconstructing the state of a complex quantum system represents a pivotal task for all quantum information applications, both for characterization purposes and for verification of quantum protocols. Recent technological developments have…
Accurately characterizing multipartite entangled states is a critical challenge in quantum information processing. In this work, we focus on applying compressed sensing techniques to efficiently estimate the fidelity of…
A novel two-qubit entangling gate for trapped-ion quantum processors is proposed theoretically and demonstrated experimentally. During the gate, double-dressed quantum states are created by applying a phase-modulated continuous driving…
Hyperfine-encoded qubits in alkali atoms have established themselves as robust platforms for quantum computing, while alkaline-earth-like elements expand the state manipulation toolbox through their rich spectrum of optical transitions and…
We present a novel method for measuring the half-life of highly charged radioisotopes by non-destructive nuclear recoil detection in a Penning ion trap. A specific emphasis is placed on $\rm ^7Be^{3+}$, which plays a crucial role in stellar…
Quantum error correction in general is experimentally challenging as it requires significant expansion of the size of quantum circuits and accurate performance of quantum gates to fulfill the error threshold requirement. Here we propose a…
Quantum error detection is essential in realizing large-scale universal quantum computation, especially for quantum error correction (QEC). However, key elements for FTQC have yet to be realized in silicon qubits. Here, we demonstrate…
Real quantum measurements almost always cause a much stronger back action than required by the laws of quantum mechanics. In particular, free-space optical detection methods for single atoms and ions such as the shelving technique, though…
We show how high fidelity quantum teleportation of light to atoms can be achieved in the same setup as was used in the recent experiment [J. Sherson et.al., quant-ph/0605095, accepted by Nature], where such an inter-species quantum state…
Boson sampling is a sub-universal model used to show quantum speed-up. However, the methods of validation to prove quantum speedup are not robust and accurate. All verification methods involve additional or little studied assumptions. Here,…
We report on an elementary quantum network of two atomic ions separated by 230 m. The ions are trapped in different buildings and connected with 520(2) m of optical fiber. At each network node, the electronic state of an ion is entangled…
Entanglement generation in trapped-ion systems has relied thus far on two distinct but related geometric phase gate techniques: Molmer-Sorensen and light-shift gates. We recently proposed a variant of the light-shift scheme where the qubit…