Dear all, Very interesting seminar today @11 AM ---------- Forwarded message ---------- From: Peter Shor <shor(a)math.mit.edu> Date: Thu, 24 Feb 2011 02:31:28 -0500 Subject: [QIP-Sem] QIP seminar, Thu 2/24, 11:00, 6-310, Sanders,Barry To: qip-sem(a)mit.edu MIT Quantum Information Processing seminar Thursday 2/24 at 11:00 in 6-310 ------------------------------------------------- Sanders,Barry (University of Calgary) Simulating Time-Dependent Quantum Dynamics On A Quantum Computer Abstract: Since 1982, when Feynman first proposed efficiently simulating Hamiltonian dynamics on a quantum computer as a way around classical- computer intractability, great advances have been achieved in developing general-purpose quantum-simulation algorithms for bounded- error solutions that fully account for all consumed computational resources. The primary focus has been on time-independent Hamiltonian evolution, but time-dependent Hamiltonian evolution is also important as it is central to quantum control and adiabatic processes. I report our efficient quantum algorithm for simulating time-dependent Hamiltonian evolution of general input states on a quantum computer provided that the Hamiltonian is sufficiently smooth. The time cost of our algorithm is close to linear in the evolution time, hence comparable to algorithms for simulating time-independent Hamiltonian evolution. Our algorithm is based on queries to an oracle holding the Hamiltonian, and we assign unit cos t per bit or qubit for oracle calls in contrast to previous work wherein an oracle query yields an arbitrary number of bits or qubits at constant cost. Our per-bit or per-qubit costing of oracle calls reveals hitherto unnoticed simulation costs even for the case of simulating time-independent Hamiltonian evolution. We also account for discretization errors in the time and the representation of the Hamiltonian. Consequently our algorithm not only enables simulation of time-dependent quantum dynamics on a quantum computer but also reduces to the time- independent evolution case and with a fair assessment of oracle-query cost. ------------------------------------------------- http://qis.mit.edu http://mailman.mit.edu/mailman/listinfo/qip-sem _______________________________________________ QIP-Sem mailing list QIP-Sem(a)mit.edu http://mailman.mit.edu/mailman/listinfo/qip-sem