diff --git a/qdax/core/emitters/multi_emitter.py b/qdax/core/emitters/multi_emitter.py
deleted file mode 100644
index 8cd0952d..00000000
--- a/qdax/core/emitters/multi_emitter.py
+++ /dev/null
@@ -1,87 +0,0 @@
-from typing import Optional, Tuple
-
-import jax
-from jax import numpy as jnp
-
-from qdax.core.containers.repertoire import Repertoire
-from qdax.core.emitters.emitter import Emitter, EmitterState
-from qdax.types import Descriptor, ExtraScores, Fitness, Genotype, RNGKey
-
-
-class MultiEmitterState(EmitterState):
-    emitters_state_tuple: Tuple[EmitterState]
-
-
-class MultiEmitter(Emitter):
-    def __init__(self, emitters_tuple: Tuple[Emitter, ...]):
-        self.emitters_tuple = emitters_tuple
-
-    def emit(
-        self,
-        repertoire: Optional[Repertoire],
-        multi_emitter_state: Optional[MultiEmitterState],
-        random_key: RNGKey,
-    ) -> Tuple[Genotype, RNGKey]:
-        assert multi_emitter_state is not None
-        assert len(multi_emitter_state.emitters_state_tuple) == len(self.emitters_tuple)
-
-        random_key, *_keys_emitters = jax.random.split(
-            random_key, len(self.emitters_tuple) + 1
-        )
-
-        all_genotypes = []
-        for emitter, emitter_state, _key_emitter in zip(
-            self.emitters_tuple,
-            multi_emitter_state.emitters_state_tuple,
-            _keys_emitters,
-        ):
-            genotype, _ = emitter.emit(repertoire, emitter_state, _key_emitter)
-            all_genotypes.append(genotype)
-
-        genotypes_tree = jax.tree_map(
-            lambda *x: jnp.concatenate(x, axis=0), *all_genotypes
-        )
-        return genotypes_tree, random_key
-
-    def state_update(
-        self,
-        emitter_state: Optional[MultiEmitterState],
-        repertoire: Optional[Repertoire] = None,
-        genotypes: Optional[Genotype] = None,
-        fitnesses: Optional[Fitness] = None,
-        descriptors: Optional[Descriptor] = None,
-        extra_scores: Optional[ExtraScores] = None,
-    ) -> Optional[MultiEmitterState]:
-        if emitter_state is None:
-            return None
-
-        list_emitter_states = []
-
-        for emitter, sub_emitter_state in zip(
-            self.emitters_tuple, emitter_state.emitters_state_tuple
-        ):
-            new_sub_emitter_state = emitter.state_update(
-                sub_emitter_state,
-                repertoire,
-                genotypes,
-                fitnesses,
-                descriptors,
-                extra_scores,
-            )
-            list_emitter_states.append(new_sub_emitter_state)
-
-        return MultiEmitterState(tuple(list_emitter_states))
-
-    def init(
-        self, init_genotypes: Optional[Genotype], random_key: RNGKey
-    ) -> Tuple[Optional[EmitterState], RNGKey]:
-        random_key, *_keys_emitters_list = jax.random.split(
-            random_key, len(self.emitters_tuple) + 1
-        )
-
-        list_emitter_states = []
-        for emitter, _key_emitter in zip(self.emitters_tuple, _keys_emitters_list):
-            emitter_state, _ = emitter.init(init_genotypes, _key_emitter)
-            list_emitter_states.append(emitter_state)
-
-        return MultiEmitterState(tuple(list_emitter_states)), random_key