diff --git a/qualtran/bloqs/data_loading/one_hot_encoding.py b/qualtran/bloqs/data_loading/one_hot_encoding.py
new file mode 100644
index 000000000..23e8a5726
--- /dev/null
+++ b/qualtran/bloqs/data_loading/one_hot_encoding.py
@@ -0,0 +1,54 @@
+#  Copyright 2023 Google LLC
+#
+#  Licensed under the Apache License, Version 2.0 (the "License");
+#  you may not use this file except in compliance with the License.
+#  You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+#  Unless required by applicable law or agreed to in writing, software
+#  distributed under the License is distributed on an "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#  See the License for the specific language governing permissions and
+#  limitations under the License.
+import attrs
+import cirq
+from attr import field
+from numpy._typing import NDArray
+
+from qualtran import GateWithRegisters, QAny, QUInt, Signature
+from qualtran.bloqs.basic_gates import TwoBitCSwap
+
+
+@attrs.frozen
+class OneHotEncoding(GateWithRegisters):
+    """
+    One-hot encode a binary integer into a target register.
+
+    Registers:
+        a: an unsigned integer
+        b: the target to one-hot encode.
+
+    References:
+        [Windowed quantum arithmetic](https://arxiv.org/pdf/1905.07682.pdf)
+        Figure 4]
+    """
+
+    binary_reg_size: int = field()
+
+    @property
+    def signature(self) -> 'Signature':
+        return Signature.build_from_dtypes(
+            a=QUInt(self.binary_reg_size), b=QAny(2**self.binary_reg_size)
+        )
+
+    def decompose_from_registers(
+        self, *, context: cirq.DecompositionContext, **quregs: NDArray[cirq.Qid]
+    ) -> cirq.OP_TREE:
+        a = quregs['a']
+        b = quregs['b']
+
+        yield cirq.X(b[0])
+        for i in range(len(a)):
+            for j in range(2**i):
+                yield TwoBitCSwap().on_registers(ctrl=a[i], x=b[j], y=b[2**i + j])
diff --git a/qualtran/bloqs/data_loading/one_hot_encoding_test.py b/qualtran/bloqs/data_loading/one_hot_encoding_test.py
new file mode 100644
index 000000000..a07ec86a8
--- /dev/null
+++ b/qualtran/bloqs/data_loading/one_hot_encoding_test.py
@@ -0,0 +1,57 @@
+#  Copyright 2023 Google LLC
+#
+#  Licensed under the Apache License, Version 2.0 (the "License");
+#  you may not use this file except in compliance with the License.
+#  You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+#  Unless required by applicable law or agreed to in writing, software
+#  distributed under the License is distributed on an "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#  See the License for the specific language governing permissions and
+#  limitations under the License.
+import attrs
+import cirq
+import pytest
+from attr import field
+from numpy._typing import NDArray
+
+from qualtran import GateWithRegisters, QUInt, Signature
+from qualtran.bloqs.data_loading.one_hot_encoding import OneHotEncoding
+from qualtran.cirq_interop.bit_tools import iter_bits
+from qualtran.cirq_interop.testing import assert_circuit_inp_out_cirqsim
+
+
+@attrs.frozen
+class OneHotEncodingTest(GateWithRegisters):
+    integer: int = field()
+    size: int = field()
+
+    @property
+    def signature(self) -> 'Signature':
+        return Signature.build_from_dtypes(a=QUInt(self.size), b=QUInt(2**self.size))
+
+    def decompose_from_registers(
+        self, *, context: cirq.DecompositionContext, **quregs: NDArray[cirq.Qid]
+    ) -> cirq.OP_TREE:
+        a = quregs['a']
+        b = quregs['b']
+        binary_repr = list(iter_bits(self.integer, self.size))[::-1]
+        for i in range(self.size):
+            if binary_repr[i] == 1:
+                yield cirq.X(a[i])
+        yield OneHotEncoding(binary_reg_size=self.size).on_registers(a=a, b=b)
+
+
+@pytest.mark.parametrize('integer', list(range(8)))
+def test_one_hot_encoding(integer):
+    gate = OneHotEncodingTest(integer, 3)
+    qubits = cirq.LineQubit.range(3 + 2**3)
+    op = gate.on_registers(a=qubits[:3], b=qubits[3:])
+    circuit0 = cirq.Circuit(op)
+    initial_state = [0] * (3 + 2**3)
+    final_state = [0] * (3 + 2**3)
+    final_state[:3] = list(iter_bits(integer, 3))[::-1]
+    final_state[3 + integer] = 1
+    assert_circuit_inp_out_cirqsim(circuit0, qubits, initial_state, final_state)
diff --git a/qualtran/bloqs/data_loading/qrom_adjoint.py b/qualtran/bloqs/data_loading/qrom_adjoint.py
new file mode 100644
index 000000000..54e9230b8
--- /dev/null
+++ b/qualtran/bloqs/data_loading/qrom_adjoint.py
@@ -0,0 +1,108 @@
+import dataclasses
+import itertools
+from typing import List, Sequence, Tuple
+
+import attrs
+import cirq
+from attr import field
+from cirq import Condition
+from numpy._typing import NDArray
+
+from qualtran import Signature
+from qualtran.bloqs.data_loading import QROM
+from qualtran.bloqs.data_loading.one_hot_encoding import OneHotEncoding
+from qualtran.bloqs.data_loading.qrom import _to_tuple
+from qualtran.bloqs.multiplexers.unary_iteration_bloq import UnaryIterationGate
+from qualtran.cirq_interop.bit_tools import iter_bits
+from qualtran.resource_counting.symbolic_counting_utils import SymbolicInt, is_symbolic, log2
+
+@dataclasses.dataclass(frozen=True)
+class QROMAdjCondition(Condition):
+    key: cirq.MeasurementKey
+    dx: List[int]
+
+    def replace_key(self, current: cirq.MeasurementKey, replacement: cirq.MeasurementKey):
+        return QROMAdjCondition(replacement, self.dx) if self.key == current else self
+
+    def resolve(self, classical_data: cirq.ClassicalDataStoreReader) -> bool:
+        y = classical_data.get_digits(self.key)
+        active = False
+        for yi, dxi in zip(y, self.dx):
+            active = not active if yi * dxi == 1 else active
+        return active
+    
+
+
+@attrs.define
+class QROMWithClassicalControls(QROM):
+    QROM_bloq: QROM = field(default=None)
+    mz_key: str = field(default="target_mzs")
+
+    def calc_dx(self, x):
+        bitstring = []
+        x_start = 0
+        for i in range(len(self.QROM_bloq.target_bitsizes)):
+            bitsize = self.QROM_bloq.target_bitsizes[i]
+            data = self.QROM_bloq.data[i][x[x_start:x_start + bitsize]]
+            bitstring.extend(iter_bits(data, bitsize))
+        return bitstring
+
+
+    def nth_operation(
+        self, context: cirq.DecompositionContext, control: cirq.Qid, **kwargs
+    ) -> cirq.OP_TREE:
+        selection_idx: int = kwargs[self.selection_registers[0].name]
+        target_regs = {reg.name: kwargs[reg.name] for reg in self.target_registers}
+        # yield self._load_nth_data(selection_idx, lambda q: CNOT().on(control, q), **target_regs)
+        # for i, d in enumerate(self.data):
+        #     target = target_regs.get(f'target{i}_', ())
+        target = target_regs.get(f'target{0}_', ())
+        # for q, bit in zip(target, f'{int(self.data[0][selection_idx]):0{len(target)}b}'):
+        #     if int(bit):
+        #         yield gate(q)
+        N = int(log2(len(target)))
+        selection_bits = iter_bits(selection_idx, self.selection_bitsizes[0])
+        for i in range(len(target)):
+            target_bits = iter_bits(i, N)
+            dx = self.calc_dx(list(itertools.chain(selection_bits, target_bits)))
+            yield cirq.X(target[i]).with_classical_controls(QROMAdjCondition(cirq.MeasurementKey(self.mz_key), dx))
+
+
+@attrs.frozen
+class QROMAdj():
+    QROM_Bloq: QROM = field()
+    num_ancilla: SymbolicInt = field(default=1)
+    mz_key: str = field(default="target_mzs")
+
+    @num_ancilla.validator
+    def num_ancilla_validator(self, field, val):
+        if is_symbolic(val):
+            return
+        if not log2(val).is_integer():
+            raise ValueError(f"num_ancilla must be a power of 2, but got {val}")
+
+    def signature(self) -> Signature:
+        return self.QROM_Bloq.signature
+
+
+    def decompose_from_registers(
+        self, *, context: cirq.DecompositionContext, **quregs: NDArray[cirq.Qid]
+    ) -> cirq.OP_TREE:
+        num_targets = len(self.QROM_Bloq.target_registers)
+        for i in range(num_targets):
+            targets = quregs[f'target{i}']
+            for target in targets:
+                yield cirq.H(target)
+        for i in range(num_targets):
+            targets = quregs[f'target{i}']
+            for j, target in enumerate(targets):
+                yield cirq.measure(target, key=f"target_mzs")
+        ancillas = context.qubit_manager.qalloc(self.num_ancilla)
+        if len(self.QROM_Bloq.selection_registers) == 1:
+            selection_regs = quregs['selection']
+        else:
+            selection_regs = [quregs[f"selection{i}"] for i in range(len(self.QROM_Bloq.selection_registers))]
+        selection_regs = selection_regs.flatten()
+        binary_int_size = int(log2(self.num_ancilla))
+        yield OneHotEncoding(binary_int_size).on_registers(a=selection_regs[-binary_int_size:], b=ancillas)
+