China’s Quantum Quandary

Elsa B. Kania

Justin Ko

Moscioni, Brian James

Elsa B. Kania

Wei Wen

Quantum measurement is the greatest problem in quantum theory. In fact, different views for the quantum measurement cause different schools of thought in quantum theory. The quandaries of quantum measurement are mainly concentrated in “stochastic measurement space”, “instantaneous measurement process” and “basis-preferred measurement space.” These quandaries are incompatible with classical physical laws and discussed many years but still unsolved. In this chapter, we introduce a new theory that provided a new scope to interpret the quantum measurement. This theory tells us the quandaries of quantum measurement are due to the nonlocal correlation and stochastic quantum potential noise. The quantum collapse had been completed by the noised world before we looked, and the moon is here independent of our observations.

Stefanie Günther, N. Anders Petersson, Jonathan L. DuBois

Quantum optimal control can be used to shape the control pulses for realizing unitary and non-unitary transformations of quantum states. These control pulses provide the fundamental interface between the quantum compiler and the quantum hardware. Most current software for quantum optimal control (e.g. Qutip [1] or Krotov [2]) is restricted to run on shared memory platforms, limiting their applicability to smaller quantum systems, in particular if interactions with the environment are taken into account. This paper gives an overview of the open-source code Quandary, which is designed to solve quantum control problems in larger open quantum systems modelled by Lindblad’s master equation. Implemented in C++, Quandary uses the message passing paradigm for distributed memory computers that enables scalability to large numbers of compute cores. Accompanied by numerical examples, this paper presents an overview on existing theoretical developments for open optimal quantum control realizing state-to-state transfer, unitary gate optimization as well as state-preparation, and presents the numerical tools and implementation aspect as realized in Quandary, for deployment on modern high-performance computing platforms.