Quantum Measurement Operations with Nanomagnets and SQUIDs

TL;DR

This paper models quantum measurement processes using coupled nanomagnets and SQUIDs within a PISCES framework, highlighting potential quantum interference effects that challenge traditional measurement assumptions.

Contribution

It introduces a quantum mechanical model of measurement involving nanomagnets and SQUIDs, demonstrating possible interference effects that could affect measurement outcomes.

Findings

Quantum interference can disrupt standard measurement operations.

A quantum model of measurement with nanomagnets and SQUIDs is developed.

Potential for designing measurement systems that exploit quantum interference.

Abstract

The low-energy behaviour of 2 coupled nanomagnets or 2 coupled SQUIDs, interacting with their environment, can be described by the model of a ``Pair or Interacting Spins Coupled to an Environmental Sea'' (PISCES). These physical systems can then be used for a measurement operation in which system, apparatus and environment are all treated quantum mechanically. We design a ``Bell/Coleman-Hepp'' measuring system, and show that in principle one may design a situation in which quantum interference between system and apparatus can upset the usual measurement operation.