arXiv subjects

Silvia Bergamini

Publications and source records attributed to Silvia Bergamini.

6 recordsLinked to original sources

arXiv2026

Efficient lambda-enhanced gray molasses using an EIT-based laser locking scheme

We present a novel implementation of lambda-enhanced gray molasses cooling in a non-standard beam geometry and with an inexpensive laser locking set-up. In contrast to the established use of resource-intensive phase locking methods, our laser system uses two independent lasers, frequency -locked to a spectral feature produced by an electromagnetically induced transparency (EIT) resonance. We show that this approach achieves sufficient coherence to enable effective gray molasses cooling without the need for costly GHz electronics, significantly reducing the complexity and cost of experimental setups and represents a step toward more accessible cold atom technologies. A wave-function Monte Carlo analysis supports the experimental findings, offering insight into the cooling dynamics of this unconventional scheme

quant-ph↗

arXiv2017

A blueprint for fault-tolerant quantum computation with Rydberg atoms

We present a blueprint for building a fault-tolerant universal quantum computer with Rydberg atoms. Our scheme, which is based on the surface code, uses individually-addressable optically-trapped atoms as qubits and exploits electromagnetically induced transparency to perform the multi-qubit gates required for error correction and computation. We discuss the advantages and challenges of using Rydberg atoms to build such a quantum computer, and we perform error correction simulations to obtain an error threshold for our scheme. Our findings suggest that Rydberg atoms are a promising candidate for quantum computation, but gate fidelities need to improve before fault-tolerant universal quantum computation can be achieved.

quant-ph↗

arXiv2015

Supersensitive measurement using single-atom control of an atomic ensemble

We analyze the operation of a novel sensor based on atom interferometry, which can achieve supra-classical sensitivity by exploiting quantum correlations in mixed states of many qubits. The interferometer is based on quantum gates which use coherently-controlled Rydberg interactions between a single atom (which acts as a control qubit) and an atomic ensemble (which provides register qubits). In principle, our scheme can achieve precision scaling with the size of the ensemble - which can extend to large numbers of atoms - while using only single-qubit operations on the control and bulk operations on the ensemble. We investigate realistic implementation of the interferometer, and our main aim is to develop a new approach to quantum metrology that can achieve quantum-enhanced measurement precision by exploiting coherent operations on large impure quantum states. We propose an experiment to demonstrate the enhanced sensitivity of the protocol, and to investigate a transition from classical to supra-classical sensitivity which occurs when using highly-mixed probe states.

quant-ph↗

arXiv2013

A cold-atoms based processor for deterministic quantum computation with one qubit in intractably large Hilbert spaces

We propose the use of Rydberg interactions and ensembles of cold atoms in mixed state for the implementation of a protocol for deterministic quantum computation with one quantum bit (DQC1) that can be readily operated in high dimensional Hilbert spaces. We propose an experimental test for the scalability of the protocol and to study the physics of discord. Furthermore we develop a scheme to add control to non-trivial unitaries that will enable the study of many-body physics with ensembles in mixed states.

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arXiv2006

Controlled Single-Photon Emission from a Single Trapped Two-Level Atom

By illuminating an individual rubidium atom stored in a tight optical tweezer with short resonant light pulses, we create an efficient triggered source of single photons with a well-defined polarization. The measured intensity correlation of the emitted light pulses exhibits almost perfect antibunching. Such a source of high rate, fully controlled single photon pulses has many potential applications for quantum information processing.

quant-ph↗

arXiv2004

Holographic generation of micro-trap arrays for single atoms

We have generated multiple micron-sized optical dipole traps for neutral atoms using holographic techniques with a programmable liquid crystal spatial light modulator. The setup allows the storing of a single atom per trap, and the addressing and manipulation of individual trapping sites.

quant-ph↗