  We report a new measurement of the beam-spin asymmetry $\boldsymbol{\Sigma}$
for the $\vec{\gamma} n \rightarrow K^+\Sigma^-$ reaction using quasi-free
neutrons in a liquid-deuterium target. The new dataset includes data at
previously unmeasured photon energy and angular ranges, thereby providing new
constraints on partial wave analyses used to extract properties of the excited
nucleon states. The experimental data were obtained using the CEBAF Large
Acceptance Spectrometer (CLAS), housed in Hall B of the Thomas Jefferson
National Accelerator Facility (JLab). The CLAS detector measured reaction
products from a liquid-deuterium target produced by an energy-tagged, linearly
polarised photon beam with energies in the range 1.1 to 2.3 GeV. Predictions
from an isobar model indicate strong sensitivity to $N(1720)3/2^+$,
$\Delta(1900)1/2^-$, and $N(1895)1/2^-$, with the latter being a state not
considered in previous photoproduction analyses. When our data are incorporated
in the fits of partial-wave analyses, one observes significant changes in
$\gamma$-$n$ couplings of the resonances which have small branching ratios to
the $\pi N$ channel.
