Quantum algorithm for linear non-unitary dynamics with near-optimal dependence on all parameters
This presentation introduces a family of identities that express general linear non-unitary evolution operators as a linear combination of unitary evolution operators, each solving a Hamiltonian simulation problem. This formulation can exponentially enhance the accuracy of the recently introduced linear combination of Hamiltonian simulation (LCHS) method [An, Liu, and Lin, Physical Review Letters, 2023].
Performance bounds for autonomous quantum error correction
Noise is widely regarded as a major obstacle to quantum computing. Fortunately, this problem can be solved efficiently due to the existence of the threshold theorem. It states that under sufficiently weak noise and universal assumptions, there always exists an active quantum error correction protocol with only logarithmic hardware overhead. One may ask: can a similar result be obtained for autonomous (passive) error correction, where noise is suppressed by natural or engineered dissipation?
Steane Error Correction with Trapped Ions
Quantum states can quickly decohere due to their interaction with the environment and imperfections in the applied quantum controls. Quantum error correction promises to preserve coherence by encoding the state of each qubit into a multi-qubit state with a high-degree of symmetry. Perturbations are first detected by measuring the symmetries of the quantum state and then corrected by applying a set of gates based on the measurements.
Observation of a finite-energy phase transition in a one-dimensional quantum simulator
One of the most striking many-body phenomena in nature is the sudden change of macroscopic properties as the temperature or energy reaches a critical value. Such equilibrium transitions have been predicted and observed in two and three spatial dimensions, but have long been thought not to exist in one-dimensional (1D) systems.
Fault-tolerant hyperbolic Floquet quantum error correcting codes
A central goal in quantum error correction is to reduce the overhead of fault-tolerant quantum computing by increasing noise thresholds and reducing the number of physical qubits required to sustain a logical qubit.
Theory of quantum circuits with Abelian symmetries and new methods for circuit synthesis with XY interaction
In this talk, I will first provide an overview of an ongoing project on symmetric quantum circuits and then discuss two related recent results from this year. The overarching goal of this project is to investigate the properties of quantum circuits constructed from k-local gates that all respect a global symmetry, such as U(1) or SU(d).
Quantum simulations with trapped ions: Thermal \lamba\phi^4 field theories and Z2 gauge theories
In this talk, Dr Bermúdez will start by reviewing the recent progress of analog quantum simulators based on crystals of trapped atomic ions. He will discuss recent experiments that exploit both the electronic and vibrational degrees of freedom to simulate spin models and bosonic lattice models.
Grant Writing Workshop
How to write successful grant proposals, pushing your writing skills to the next level. Our speaker will provide an overview of grant writing and discuss successful strategies. Come prepared with your questions.
You can send your questions in advance to rqs-seed@umiacs.umd.edu.
Lunch will be provided.
Leveraging Hamiltonian Simulation Techniques to Compile Operations on Bosonic Devices
Circuit QED enables the combined use of qubits and oscillator modes. Despite a variety of available gate sets, many hybrid qubit-boson (i.e., oscillator) operations are realizable only through optimal control theory (OCT) which is oftentimes intractable and uninterpretable. We introduce an analytic approach with rigorously proven error bounds for realizing specific classes of operations via two matrix product formulas commonly used in Hamiltonian simulation, the Lie–Trotter and Baker–Campbell–Hausdorff product formulas.