arXiv subjects

Antonis Kyprianidis

Publications and source records attributed to Antonis Kyprianidis.

4 recordsLinked to original sources

arXiv2026

In-Situ Rewiring of Two-Dimensional Ion Lattice Interactions Using Metastable State Shelving

Trapped-ion lattice geometries, which determine the interactions between trapped-ion qubits, are typically governed by the balance of Coulomb repulsion forces with the external trapping potential. Here we demonstrate how the effective ion lattice geometry and resulting qubit-qubit interactions may be reconfigured in-situ, by shelving specific ions in metastable states outside the qubit subspace. Using a triangular lattice of three $^{171}$Yb$^{+}$ ions, we optically pump selected ions into the long-lived $^2F_{7/2}$ state. We then apply a global Ising-like Hamiltonian to the system and verify that the shelved qubits are fully removed from participation in the quantum dynamics. We characterize the metastable state lifetime in the presence of laser-driven ion-ion interactions, finding a deshelving rate that is orders of magnitude slower than the spin-spin interaction rate and scales quadratically with applied laser intensity.

quant-ph↗

arXiv2024

Measurement-Induced Heating of Trapped Ions

We experimentally study the heating of trapped atomic ions during measurement of their internal qubit states. During measurement, ions are projected into one of two basis states and discriminated by their state-dependent fluorescence. We observe that ions in the fluorescing state rapidly scatter photons and heat at a rate of \mbox{$\dot{\bar{n}}\gtrsim 2\times 10^4$ quanta/s}, which is orders of magnitude faster than typical anomalous ion heating rates. We introduce a quantum trajectory-based framework that accurately reproduces the experimental results and provides a unified description of ion heating for both continuous and discrete sources.

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arXiv2023

Interaction graph engineering in trapped-ion quantum simulators with global drives

Trapped-ion quantum simulators have demonstrated a long history of studying the physics of interacting spin-lattice systems using globally addressed entangling operations. Here, we seek to broaden and delimit the classes of effective spin-spin interactions achievable using exclusively global driving fields. We find that new categories of interaction graphs become achievable with perfect or near-perfect theoretical fidelity by tailoring the coupling to each vibrational mode of the ion crystal, or by shaping the trapping potential to include specific anharmonic terms. We also derive a rigorous test to determine whether a desired interaction graph is accessible using only globally driven fields. These tools broaden the reach of trapped-ion quantum simulators so that they may more easily address open questions in materials science and quantum chemistry.

quant-ph↗

arXiv2021

Observation of a prethermal discrete time crystal

The conventional framework for defining and understanding phases of matter requires thermodynamic equilibrium. Extensions to non-equilibrium systems have led to surprising insights into the nature of many-body thermalization and the discovery of novel phases of matter, often catalyzed by driving the system periodically. The inherent heating from such Floquet drives can be tempered by including strong disorder in the system, but this can also mask the generality of non-equilibrium phases. In this work, we utilize a trapped-ion quantum simulator to observe signatures of a non-equilibrium driven phase without disorder: the prethermal discrete time crystal (PDTC). Here, many-body heating is suppressed not by disorder-induced many-body localization, but instead via high-frequency driving, leading to an expansive time window where non-equilibrium phases can emerge. We observe a number of key features that distinguish the PDTC from its many-body-localized disordered counterpart, such as the drive-frequency control of its lifetime and the dependence of time-crystalline order on the energy density of the initial state. Floquet prethermalization is thus presented as a general strategy for creating, stabilizing and studying intrinsically out-of-equilibrium phases of matter.

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